The Veterinarian Magazine July 2023

TheVeterinarian

Cats under attack in the European virus outbreaks

Australian ecologist wins US Quest Award

Ecologist Terry Ord, an Associate Professor and Director of Research at the University of NSW’s School of Biological, Earth and Environmental Sciences is the recipient of the US Animal Behavior Society’s Quest Award. He is the first Australian to win this Award, which is based on multiple nominations from senior researchers and discipline leaders across the US, and recognises scientists making an outstanding seminal contribution in animal behaviour. Ord is only the second Australian to win any ABS award.

Although the win took Ord by surprise, he said he was thrilled to receive such validation for his behavioural observation fieldwork that has provided a detailed understanding of why animals behave the way they do, and why that behaviour may vary among closely related species.

Feline coronavirus is to blame for the death of thousands of cats in Cyprus, according to experts. The virus which does not infect people and is not linked to COVID-19, appears to be a more virulent strain and is causing more severe illness than previously outbreaks.

Charalampos Attipa, a senior lecturer in veterinary clinical pathology at the University of Edinburgh and one of the scientists investigating the outbreak, said that although the number of deaths has not been confirmed, the development was “very alarming”.

COVID-19 can infect cats and may have potentially led to the indirect changes in the feline virus,

due to antibodies carried by cats previously infected with the virus. Researchers have conducted gnome testing to determine if the feline virus has mutated.

Meanwhile, Polish authorities are investigating an outbreak of highly pathogenic H5N1 bird flu in domestic cats. Although sporadic infections of H5N1 influenza in cats have previously been reported, “this is the first report of a high number of infected cats over a wide geographical area within a country”, the World Health Organization said.

■ JULIA GARDINER

“Studying animal behaviour and evolution in the wild can be really hard. Sometimes you wonder whether it’s all worth it, especially when you’re struggling with conditions in the field. If you’re not soaked to the bone, you’re sweltering in the heat, so to have some of the world’s leading scientists tip their hat to you like this is validation that what I’m doing really is worth all the hard work. It means everything when others recognise you’ve done something of value,” he said. To page 30

Sudden horse deaths under investigation

Veterinarians are working with Agriculture Victoria to examine the cause of several sudden deaths in horses that have occurred on separate properties since early July.

The state’s Chief Veterinary Officer Graeme Cooke said an investigation is underway to understand why 13 horses have died on five separate properties in south-east Melbourne (two properties), Mornington Peninsula, Colac and Ballarat.

“The investigation is in the early stages. It is not yet known what has caused these deaths and to date common links are not evident,” Cooke said in a statement.

It is believed the horses died quickly with short term

non-specificindications of illness.

Agriculture Victoria is calling on any owners who have not reported deaths to contact them or their veterinarian to assist with investigations.

Cooke said early testing for some known diseases in horses has been negative.

“Comprehensive testing for a range of disease, and importantly, non-disease causes, is underway,” he said.

“I thank those owners and veterinarians who have been affected for their assistance in providing information to date.”

Cooke said early assessment and collection of a range of samples is

critical to this type of investigation.

“We know this is a difficult time for horse owners, that’s why we are working with veterinarians and a range of experts to find answers," he said.

“Please do not share unconfirmed information online or on social media.”

Agriculture Victoria said investigations into multiple horse deaths on a single property focus on infectious causes and ingestion of toxins.

Horse owners have been reminded to ensure their Property Identification Code details are up to date.

■ SAM WORRAD

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Vet schools feeling the squeeze Red ant threat inching closer to NSW farmers

The failure to prevent red fire ants moving south from Queensland has prompted serious calls from New South Wales farmers and industry bodies for the creation of border checkpoints and a large increase in government funding.

With the ants now just kilometres from the NSW border, areport leaked by the Invasive Species Council claims the current funding commitments of another $60million next year, as well as $80million from the NSW government, will not be enough to control the ants, with fears the estimated cost to livestock and horticultural industries could be over $2billion per year if the ants spread.

Invasive Species Council advocacy manager Jack Gough said his organisation has already seen a 40 per cent reduction in beef productivity in areas where fire ants were prevalent.

Red fire ant venom can cause allergic reactions, anaphylaxis and sometimes death in susceptible people and in livestock. Stings around the eyes, mouth and nose of livestock can lead to blindness and suffocation, as well as preventing animals from reaching food or water, leading to starvation and dehydration.

Additionally, there are more than 50 agricultural and horticultural crops, as well as turf and nursery species susceptible to fire ants, which tunnel through the plants roots and stems.

Greenlife Industry Australia (GIA), the national horticulture sector peak body, agrees funding needs to be dramatically increased to combat the pest.

Chief executive Joanna Cave said the federal government's $60 million in 2023 was only one-tenth of the funding experts said was required each year, with a previous review of the National Red Import Fire Ant Eradication Program estimating it would cost around $250 million a year to eradicate the pest by 2030.

NSW farmers recently gathered in Sydney to call on the government to reintroduce checkpoints to inspect goods travelling from Queensland into NSW.

■ JULIA GARDINER

A review of Australia’s veterinary schools has found that at least one is at imminent risk of closure due to financial pressure, in a country already facing asevere shortage of vets in both city and rural areas.

The two-year study commissioned by Veterinary Schools of Australia and New Zealand (VSANZ) recommended a 30 per cent increase in student funding. VSANZ chair Nigel Perkins said the response from providers was that veterinary science was a very important discipline but “these are difficult and challenging times and universities are having to make difficult decisions about prioritisation and budgets”.

“The pressures are now so large there is genuine discussion from at least one university about whether or not veterinary science will continue to be offered,” Perkins said.

The report found that although the number of vets graduating each year will have increased from fewer than 500 in 2008 to an estimated 900 by 2025, almost 80 per cent of practices have vacancies every year, with 31 per cent of these taking more than a year to fill, or remaining unfilled, with the trend incities to larger clinics with access to work-life balance and professional support more available than in small animal and specialist practices.

As a means of controlling the cost of studies, the report recommends more undergraduate specialisation as an alternative to turning out “all-rounders” however, Sydney University’s dean of

More true blue than hybrid

Despite long-held fears dingoes (Canis dingo) were breeding themselves into extinction, the findings of a study published recently in the journal Molecular Ecology has suggested that although the species is largely maintaining its identity,areview into its management and conservation practices needs to be considered.

Lead author Kylie Cairns, a conservation biologist and research fellow at the University of New South Wales’ School of Biological, Earth and Environmental Sciences, said earlier dingo studies relied on a relatively small number of genetic markers and a limited reference population. This had overestimated the amount of dog ancestryin dingo samples sometimes by over 30 per cent and resulted in animals being identified as crossbred when they were pure dingoes, or a historical backcross that included asingle dog ancestor four or five generations in the animal’s past.

“Reliance on outdated DNA testing methods led to the belief that dingo–dog hybridisation was much more common than it really was. Most dingoes in the wild are pure dingoes, and we found the remaining animals are more dingo than anything else. Even in the parts of Australia where dingo-dog hybridisation is higher, it isn’tthe pervasive threat we’ve been led to believe. With this new test, we looked at 195,000 points across the genome compared with just 23 previously,and it provided a huge step up in reliability and accuracy,” Cairns said.

The dingo is understood to have been in Australia for between 5,000 and 11,000 years. The study identified four distinct wild dingo populations across the mainland, each with significant regional variations. In Victoria, where previous reports suggested the pure dingo population was as small as four per cent,

the study found 87.1 per cent of animals tested were pure dingoes and 6.5 per cent were historical dingo backcrosses with more than 93 per cent dingo ancestry.

Similarly, in New South Wales and Queensland, where dingo-dog hybridisation is assumed to be pervasive, most animals were found to be pure dingoes, and only two wild canids had less than 70 per cent dingo ancestry. Likewise little evidence of hybridisation in the dingo population was found in the Northern Territory, South Australia, and Western Australia.

“While there has been some hybridisation in the past, it’s not occurring at a rapid pace today,and where it does happen, we can see the offspring of the hybrids returning to their dingo roots over timeand it’s possible some dog DNA has integrated into the dingo genome because it’sprovided an evolutionaryadvantage. This is something we plan to investigate in future research,” Cairns said.

Because of the widely-held view there is widespread dingo–dog hybridisation, dingoes, dingo-hybrids, and feral domestic dogs are all considered invasive species under biosecurity legislation, and subject to eradication measures like aerial baiting or trapping across parts of Australia’smainland, including National Parks where native animals are protected.

Senior author Mike Letnic, an applied ecologist and conservation biologist at UNSW’sSchool of Biological, Earth and Environmental Sciences, said the study’s more advanced approach, that used higher-density genomic data, was able to assess dingo populations more accurately It could also help inform management strategies with the best-available evidence since although dingoes were a threat to some livestock, they were not a pest in all contexts.

veterinary science, Jacqueline Norris, said the sector needs to encourage students to remain in general practice.

“[Some] people don’t feel comfortable having to deal with everything,” she said.

“It’s not about the money, it’s about feeling able to deal with all the different practices. The key element is a restructure of the funding models. Every vet school is under the pump financially,” Norris said.

With government grants and domestic student fees currently covering only about two-thirds of the cost of courses, the panel made 25 recommendations on overhauling vet education, including entry measures to assist rural students; paid apprenticeships for training on the job; more specialisation for students in undergraduate courses; and a bonding scheme to give HECS debt relief to graduates who work in the country.

■ JULIA GARDINER

“Environments without dingoes can be overrun by kangaroos, foxes and feral cats. This can result in significant changes to vegetation and impact the survival of other native animals. Dingoes play a crucial role as apex predators in maintaining ecosystem function and biodiversity,so there’s a real need find a balance in management and ensure there are places in the landscape where we maintain populations,” he said.

Cairns agreed the term ‘wild dogs’ obscured the reality that many pure dingoes and dingo-dominant backcrosses were being needlessly killed.

“It’s convenient to paint all dingoes as wild dogs. But in fact, no other native species is treated in quite the same way as the dingo, which is subject to lethal control measures across all landscapes, including ones where they should be protected,” she said.

The study found lethal control methods, particularly during dingo breeding season, may inadvertently increase the risk of hybridisation by reducing the availability of pure dingo mates, although more research will be required to confirm this link.

“While we don’thave many hybrids running around like previously suggested, where dingodog hybridisation does occur, it’s in regions where intensive lethal control is used and where there are higher numbers of pet domestic dogs,” Cairns said.

The study also recommended a redefinition of the term ‘dingoes’ when future policy is drafted, to ensure it includes historical dingo backcrosses with 93 per cent or more dingo ancestry,and to distinguish them from ‘feral domestic dogs.’

“Doing so will more accurately reflect the identity of wild canids in Australia and acknowledge the value of dingoes as a native and culturally significant species,” she said.

Jacqueline Norris

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Evolving to co-exist

In the mid-1990s, when scientists first discovered the facial tumour disease responsible for ravaging Tasmanian devil populations, few of them would have ever imagined that studies of the disease and its evolutionwould still be occurring 20 years on. While initial fears DFTD could result in the extinction of devils in the wild have abated, and insurance populations across the country ensure the species’ long-term future is secure, the results of a recently published international study in the journal Evolutionary Applications suggest at least one devil population in the wild is learning to co-exist with the disease. This could result in DFTD being considered endemic rather than an epidemic.

Disease ecologist and the study’s lead author Rodrigo Hamede, senior lecturer at the University of Tasmania’s School of Natural Sciences, said very few of the world’s wildlife diseases have had the opportunity to be studied so

extensively as DFTD, and ongoing international research into various aspects of the disease has also helped provide a model for scientists studying future emerging wildlife diseases.

“These two decades of studies offer a lot of important messages as very few diseases in the world have been studied from early emergence throughout their epidemic, and where hundreds of tumour and devil genomes have been sequenced throughout their evolution,” Hamede said.

Between 2006 and 2018 the West Pencil Pine’s population of devils in the state’s northwest was monitored four times a year, for two weeks. From the data collected during those 12 years, 159 tumour genomes were sequenced and analysed to assess the dynamics of tumour variants. The findings of Hamede’s observational study showed that DFTD reached its peak of genetic diversity shortly after the disease arrived in the area during 2006.

“We knew there would be a selective process in the tumour itself as it fine-tuned its optimum virulence. Over the next decade we found genetic diversity of the tumour gradually decreased, and while this was happening some tumour variants weeded themselves out while others became fixed. This coincided with lower infection rates. Essentially what we found was an interaction between infection

dynamics and tumour variants. These responses maximised DFTD’s own virulence suggesting devils and tumours can co-exist in the long-term in the absence of management intervention – and we did no intervention,” he said. Now DFTD has transitioned to being an endemic disease devils will need to adapt to live with it according to Hamede, although monitoring will continue Topage 30

Out-of-shape snakes filled with toxic chemicals

High levels of toxic chemicals have been found in the livers of wild tiger snakes in Perth’s urban wetlands. A study recently published in Science of the Total Environment reported the livers of the tested snakes were found to contain chemicals previously used in firefighting foam, as well as those in common household goods, such as cookware and textiles.

The per- and polyfluoroalkyl substances (PFAS) found in the snakes are a group of synthetic chemicals which are difficult to break down and have been found to make their way into the water and air intake of humans, animals and plants.

Researchers from Curtin University, the CSIRO, and Western Australia's Department of Water and Environmental Regulation, and

Vietnam's Nguyen Tat Thanh University studied the livers of the snakes to better understand the effects of PFAS, as long-term health impacts of the chemicals are largely unknown, despite many PFAS being banned.

“Tiger snakes in Perth's urban wetlands are ingesting these harmful chemicals and are noticeably skinnier and appear sickly compared to healthy tiger snakes,” lead researcher Damian Lettoof, of Curtin University and the CSIRO said.

“They are also experiencing poor muscle and body tone, as well as decreased energy levels.”

The most common PFAS chemical found in the snakes was PFOS, or perfluorooctanesulfonic acid, commonly used in firefighting foam until it was banned in Australia in the early 2000s.

The durability of the chemicals is part of the reason researchers were not surprised to find the chemical still present in animals decades later, as the wetlands get stormwater from surrounding industrial and residential land, and seepage from landfill.

Given most exposure to pollution in snakes comes from their diet, researchers will now begin testing PFAS levels in other animals that live in the wetlands, to determine if they too have concentrated levels of the chemicals.

Lettoof said more research is needed to determine if PFAS exposure could affect the survival of the snakes, but the study provides an important baseline on how the chemicals could be hurting them.

■ JULIA GARDINER

Rodrigo Hamede

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Train Up a Pup appeal targets $1m

The Petbarn Foundation recently launched its tenth annual appeal to raise funds for Seeing Eye Dogs. This year, the Foundation is aiming to raise $1million on behalf of Vision Australia, with the funds being earmarked for training 20 Seeing Eye Dogs. “We’re very proud this partnership with Vision Australia is now in its tenth year and has been instrumental in supporting Australians who are blind or have low vision with these amazing dogs who provide companionship, independence and contribute to a better quality of life,” Janelle Bloxsom, Petbarn Foundation Manager said. “We are aiming to again reach the $1million milestone with 100% of donations going directly to Vision Australia to help train up Seeing Eye Dog puppies and make an invaluable difference to the lives of another 20 Australians.”

According to Vision Australia’s estimates, around 453,000 people across the country are blind or have low vision, and this figure expected

toincrease to 564,000 by 2030. As a result, more Seeing Eye Dogs are urgently needed to assist Australians challenged by blindness or low vision so they can navigate everyday tasks more confidently and independently. Training aSeeing Eye Dog costs over $50,000 and takes up to two years, with puppies beginning basic socialisation skills training at eight weeks of age with volunteer carers. These volunteer carers are supported by puppy development trainers until the animals reach approximately 12 months of age, when the dogs progress to expert training with a specialised instructor for up to five months to become qualified and operational Seeing Eye Dogs.

Rolf Geerling, Regional Client Service Manager for Vision Australia Sydney North, can attest to the profoundly positive impact of having aSeeing Eye Dog can have. He has had two Seeing Eye Dogs, first Echo (who he kept upon her retirement after ten years), and then Stella. “Echo changed my life. We were inseparable for ten years – she was my rock,” Geerling said. “When you have low vision, you can be surrounded by a crowd and still feel utterly alone. But all it takes is a little lick from my faithful companion to reassure me that everything will be ok and that I’ll never be alone.” He hopes that donors across the country will dig deep to support the Petbarn Foundation Seeing Eye Dog Appeal, particularly since he has first-hand experience of how significantly these specially trained animals can influence the life of a person with blindness or low vision. “These wonderful dogs – they transform your life,” Geerling said. “Without the generous help from Petbarn, we couldn’t lead anormal life.”

Over the past decade, the Petbarn Foundation has raised $6.169 million on behalf of Vision Australia and has supported 125 dogs on their journey from puppies to fully trained Seeing

Eye Dogs. The most recent campaign to “Train Up a Pup” commenced on 26 June 2023, with donations being encouraged at Petbarn stores and on their online platform. Vision Australia CEO Ron Hooton is grateful for ten years of partnership with the Petbarn Foundation and hopes it continues long into the future, noting Petbarn’s Seeing Eye Dogs Appeal is the biggest annual fundraiser for Vision Australia’s Seeing Eye Dogs. “By donating, you’re not only helping us train and provide Seeing Eye Dogs to Aussies who need them, but you’re giving someone the gift of greater independence,” he said. “I want to say a big thank you to all the Petbarn customers who have supported us over the past ten years; we really appreciate it. We’re looking forward to the next ten years continuing to help Australians who are blind or have low vision by training up as many Seeing Eye Dogs as possible.”

Donations to the Petbarn Foundation Seeing Eye Dogs Appeal can be made at any Petbarn store, or online at www.petbarn.com.au/seda.

■ JAI HUMEL

Queensland practices win leadership awards

Two Queensland-based veterinary practices have been victorious at the 2023 Australasian Veterinary Leadership Awards, winning Best Led Practice and Best Team Leader.

The 2023 Australasian Veterinary Leadership Awards, hosted by Lincoln Institute of Veterinary Business, celebrate the achievements of veterinarypractices and individuals overcoming systemic workforce challenges, including mounting pressures on mental health.

Michael Powell, veterinarian and co-director of Lincoln Institute of Veterinary Business, said the awards aim to shine a spotlight on those who are creating positive change through effective and exemplary leadership, in turn inspiring their peers to follow in their footsteps.

The 2023 Australasian Best Led Practice Award winner is Animal Options Vet Clinic of Ormeau, Queensland. The clinic is recognised as the most outstanding veterinarypractice in Australia and New Zealand to excel across 18 key selection criteria that evaluate workplace culture, human resource management, and business acumen.

“This year’s winner of the 2023 Australasian Best Led Practice Award, Animal Options Vet Clinic, embodies humility, self-awareness, and personal accountability,” Powell said.

“Most importantly, they create meaning from adversity and never lose sight of their purpose, leading to a strong theme of psychological safety, respect, and care for each other.”

The 2023 Australasian Best Team Leader Award winner is Tanya Kunzel from Ripley Vet Hospital in Ipswich, Queensland.

Kunzel is the successful nominee from a pool of 600 delegates in Australia and New Zealand who is selected based on 12 key selection criteria that evaluate personal leadership, teamwork, and professional excellence.

“Ms Kunzel has demonstrated exceptional leadership in all aspects of practice life,” Powell said.

“As the Practice Manager,she has managed the competing demands of clients and the clinical team through extraordinarily difficult times as the industry resets, following the toughest years the industry has ever faced.”

“There is tremendous power in recognising achievement in an often-neglected discipline, such as leadership. This type of peer recognition inspires other veterinary practitioners to push the boundaries on what is possible for the industr y and prioritise worker wellbeing,” he said.

“Lincoln Institute of Veterinary Business is a training organisation

Weather and population density may increase spread of toxoplasmosis

that specialises in promoting more effective leadership in veterinary practice. It is run by veterinarians who have enjoyed long and fulfilling careers, as well as the distinction of running verysuccessful veterinarypractices.

“Besides our extensive work within the industr y, it is this intimate understanding of the specific leadership challenges that so often stand in the way of success in veterinar y practice that makes us well positioned for identifying and recognising this talent.

“That, coupled with our passion to create a movement for change for the better in the sector motivates us to do so.”

For further information, visit lincolninstitute.com.au.

Results of an international study led by Sophie Zhu, a PhD candidate at the University of California, Davis, School of Veterinary Sciences, suggest that wild, stray, and feral cats living in areas with higher population density tend to shed a greater amount of the Toxoplasma gondii,the parasite that causes toxoplasmosis disease.

Although a mild-to-severe disease in humans, all warm-blooded vertebrates are vulnerable to toxoplasmosis infection, which can cause abortion in sheep and goats. Marine wildlife is also susceptible to the parasite through its oocyst stage accumulating in soils that are then flushed into marine environments following a heavy rainfall.

Prior toxoplasmosis research has focused on the shedding of oocysts from owned domestic cats, but Zhu’s team analysed data from 47 previously published studies on both wildcats, To page 30

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QUARANTINEVET ADAYINTHELIFE OFSANDEEPKAUR:

elcome back to A Day in the Life, our new feature exploring what a typical day looks like in the life of a notso-typical veterinarian. This month we caught up with Dr Sandeep Kaur, a veterinarian who works for the Department of Agriculture, Fisheries and Forestry (DAFF) at the Post Entry Quarantine (PEQ) facility in Mickleham, Victoria.

Originally hailing from India, Sandeep completed aBachelor’s degree in Veterinary Science and Animal Husbandry in her country of birth before moving to Australia with her husband, daughter and mother-in-law in 2005. Since calling Australian home, Sandeep has completed her Bachelor’s degree in Veterinary Sciences (again), graduating from the University of Melbourne in 2008. She ran a small animal clinic in Melbourne before joining the Australian Public Service and has been with DAFF for more than six years. Sandeep ’s work at PEQ is characterised by variety, not least because PEQ is the only facility in Australia for imported animals to be quarantined upon arrival in this country. “There are thousands of dogs, cats, horses, birds (and eggs) imported into Australia each year, along with a smaller number of alpacas and small ruminants,” Sandeep said “My role is to ensure all animals released from PEQ comply with their import conditions, and to look after the animals’ health and welfare during their stay at PEQ.”

The two main aspects of Sandeep ’s job –compliance and animal welfare – require her to split her time between applying her veterinary knowledge both at her desk and at the PEQ facility’s stables, kennels, and cattery. While at her desk, Sandeep assesses whether animals in quarantine are compliant with their import conditions and that their official health certificate is correct and up to date. She identifies any noncompliances and then categorises these from minor to critical. “Non-compliances can be related to pre-export preparation or can be clinical signs an animal is showing while under biosecurity control at PEQ,” she said. “I liaise with numerous stakeholders, such as importers, exporters, testing laboratories, overseas competent authorities and many more to ensure non-compliances are resolved.”

According to Sandeep, most non-compliances can be resolved at PEQ after treating or testing the animals concerned. Sometimes, however, thereare cases of critical non-compliance which cannot be managed onshore, and those animals have to be re-exported to protect Australia’s biosecurity.“The critically non-compliant cases constitute the most challenging part of my job,” Sandeep said. “These cases are often complex, and the owners and importers have invested so much into these animals, who they often consider to be one of the family, so emotions run high. Ido feel very bad for families and especially for pets in cases when we have to re-export.”

When she is not at her desk, Sandeep can be found at PEQ’s stables overseeing routine testing on imported horses, or out in the kennels or cattery carrying out treatments, collecting samples and inspecting the many dogs and cats who come through the quarantine facility. Animals are inspected throughout their quarantine period, not just prior to their release, so much of Sandeep ’s time is occupied by completing health checks and providing animal care. “I really enjoy seeing the variety of breeds and types of animals in our care,” she said, providing the example that while visiting the PEQ kennels she might encounter bite trained dogs, military working dogs and show dogs in addition to dogs who are regular household pets. “There is no shortage of diversity in the work, animals and people here at PEQ, and I feel privileged to play my part in keeping Australia free of exotic pests and diseases.” To page 10

In Sandeep ’s experience, working for DAFF is totally different from the veterinary work she has done in the past. “We monitor imported animals for signs of any infectious or exotic diseases, and test and/or treat them only if there is any suspicion of exotic disease,” she explained. “Animals with health issues that do not pose biosecurity threats are treated by private vets at PEQ, or they are transferred to an emergency care facility if they cannot be managed onsite and require intensive care.”

At times, working on one of the front lines defending Australia’s biosecurity can take Sandeep away from PEQ and can also necessitate her coming in at odd hours. “When I am oncall, I must be available 24/7 and sometimes my job requires me to come to PEQ late at night or early in the morning, depending on when horse flights arrive,” she explained. “Sometimes I might have to head off to the airport to do an arrival check on an assistance dog, or to facilitate some staff training for the biosecurity officers with whom we

work closely.” In addition, Sandeep also mentors and supports other vets at PEQ and shares insights with the policy team to improve import policies and processes. Sandeep recently received the Excellence Award in recognition of her diligent work identifying critical non-compliance.

Not surprisingly, the most rewarding part of Sandeep’s job often coincides with animals being released from quarantine when they finish their stay at PEQ. “Reuniting animals with their families after a long process gives me akind of satisfaction which ishard to explain,” she said. One can only assume the pets and their owners share her joy.

And now, to conclude our Day in the Life with Sandeep Kaur, we have the CREATURE QUESTIONS we will be ask our featured veterinarian each month.

Do you currently have any pets?

Ido not have any pets at home currently because an elderly family member has some health issues and allergies.

What is your favourite animal?

Ilike dogs and horses better than cats.

If you could transform into any animal, what would you be and why?

Iwould be a horse, because horses are very graceful, strong and focussed creatures.

DO YOU HAVE SOMETHING TO SAY?

Is thereatopic you’ve wanted to tell everyone about?

Have you ever thought you would like to write a clinical review but don’tknow whereto start? Do you have a hobby or historythat you think vets everywhere would like to learnmoreabout? Then don’t delay – email The Veterinarian at editor@vetmag.com.au and let us know – because your words could be in the pages of next month’sissue!

‘There is no shortage of diversity in the work, animals and people here at PEQ, and Ifeel privileged to play my part in keeping Australia free of exotic pests and diseases.’

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Selling subject to…

When you are selling your practice, signing the sale contracts is a milestone to be celebrated. It means that you’ve agreed with a buyer on all the variables involved in the price and terms of the deal.

What many people will be surprised to hear, is that even though you have the signatures on thecontract, it usually doesn’t mean that the deal isn’t locked inyet.

Most contracts that are signed arenot unconditional on the date that they are signed. The deal is usually still subject to some “conditions precedent” that need to be met before the deal is set in stone.

Most practice sale agreements will be subject to the following conditions precedents:

Finance

While a buyer should have sought out and secured finance before signing the contract, the negotiated terms are not final until there is a signed contract. As such, the finance on the practice sale cannot be unconditional until the practice sale and premises lease/sale contracts are signed and reviewed by the bank.

Due Diligence

When a business is for sale, buyers should be given enough information to evaluate the business and

come up with an offer. The information provided at this initial stage usually includes a prospectus/ IM, Profit and Loss reports, software reports and a copy of the lease on the premises.

However, when an offer is accepted, abuyer, their lawyer and their bank will often need additional information to verify that the information given is correct and that the business is operating correctly. Financial due diligence requests might include tax returns, bank statements and/or BAS statements. Legal due diligence requests might include checking contracts with staff, radiation licence, trademarks, orazoning permit on the building (note, these are examples and not anexhaustive list).

Once an offer is accepted, drafting contracts can take several weeks; there is no reason why this period (between when an offer is accepted and contracts are ready to be signed) cannot be used by the buyer to complete due diligence, such that the contracts signed are NOT subject to due diligence.

However, sometimes due diligence may not have been able to have been done in time and contracts need to be signed subject to due diligence.

Premises lease or sale

Most practices are bought on the understanding that they will be able

to continue practicing in their current location. To secure this, the buyer needs the practice sale contract to be subject to either a premises sale or lease.

It is often possible to negotiate and sign the practice sale agreement at the same time as the premises lease or sale agreement, such that the practice sale is not delayed by premises lease negotiations.

Seller work contract

Many deals will be subject to the vendor working post sale for a period of time. When this is the case, the contract of sale might be subject to the signing of the vendor’s post-sale work contract.

Simon Palmer is the Managing Director of Practice Sale Search, Australia’s largest vet practice brokerage. If you’d like more information on practice sales or want to have a confidential discussion about your practice’s circumstances, email Simon Palmer at info@practicesalesearch. com.au or call 1300 282 042.

Striving for long term

-

Animal health and agricultural productivity in low- and middleincome countries have been the focus of research for development (R4D) projects for decades, with varying levels of success when considering the long-term sustainability of interventions. Many of these projects have been funded, designed and implemented by researchers from high income countries, and therefore risk neglecting the cultural nuances and complex country histories that can influence their success. This opinion piece suggests three broad recommendations: (1) implementing culturally congruent practices to improve disease control and prevention practices at the village level; (2) promoting public-private partnerships to improve control oftransboundary animal diseases; and (3) improving national animal health and veterinary services and their governance to improve disease surveillance, control and prevention. Development researchers need to consider implementing these approaches in future projects to improve the suitability and sustainability of interventions and acknowledging the current technical capacity of host countries. Foreign donor organisations need to ensure their funding guidelines and reporting requirements allow for these recommendations to be adequately implemented.

IBJMacPhillamy1,M J Nunn2,T S Barnes3,R Bush4,J-A L M L Toribio4

Acta Trop. 2023 Aug;244: 106946.doi: 10.1016/j.actatropica.2023.106946.

1The University of Sydney School of Veterinary Science, Camden, NSW, Australia. Electronic address: isabel.macphillamy@ausvet.com.au.

219 Macrossan Avenue, Bannockburn, Victoria 3331, Australia.

3The University of Queensland, School of Veterinary Science, Gatton, QLD, Australia.

4The University of Sydney School of Veterinary Science, Camden, NSW, Australia.

Decision-making and moral distress in veterinarypractice: what can be done to optimize welfare within the veterinaryprofession?

Veterinarians stand in many contradictorypositions, such as moral and ethical representatives of animals and their welfare and the clinic owner,which makes income for them and their families. The article will look at factors in decision-making significantly impacting veterinary professionals' mental health. Distress is caused by high societal pressure, as veterinarians must fulfill their profession's requirements. Together with working conditions, it negatively impacts their mental health. The article emphasizes the need for veterinaryprofessionals and futureveterinaryprofessionals for proficiency in animal welfare, animal ethics, and primarily moral decision-making. Thus, critical thinking and ethical decision-making should be discussed morein the profession and veterinary education.

Martin Florian1,Lenka Skurková1,L˘dia Mesarèová1,Monika Slivková1,Jana Kottferová1

JVet Med Educ. 2023 Jun 5; e20220073.doi: 10.3138/jvme-2022-0073.

1Department of Public Veterinary Medicine and Animal Welfare, Workplace of Applied Ethology and Professional Ethics, University of Veterinary Medicine and Pharmacy in Ko‰ice, 041 81 Ko‰ice, Slovak Republic.

Associations between canine hookworm infection and dog owners’ awareness, perception, and behaviour: a cross sectional study in Brisbane, Queensland, 2019 2020

Canine hookworms are found globally, and infections have been recorded in domestic dogs visiting dog parks in Queensland, Australia. Some canine hookworms also present a risk of zoonotic transmission to humans. Potential transmission of hookworms can occur in the household and at public places because of lack of owner awareness and poor coverage of canine deworming. Between April 2019 and March 2020, faecal samples from owned dogs werecollected from 39 dog parks in metropolitan Brisbane, Queensland, and tested for the presence of hookworm eggs using faecal floatation technique. Dog owners who provided samples wererequested to complete a survey on their awareness, perceptions and behaviour regarding the risks and consequences of canine parasitic infection. Associations between dog owner demographics and responses to the survey were measured using Goodman and Kruskal's gamma. Statistical associations between canine hookworm infection in dogs and their owner's responses werequantified using a two-sample Wilcoxon rank-sum test. Atotal of five canine faecal samples from 175 respondents were found positive for hookwormeggs, corresponding to a sampleand park-level prevalence of 2.86% and 12.82%, respectively.

Female dog owners werefound to be more aware of the importance of regular deworming of their dogs (|ψ =0.405). Our results indicate that hookworm infection was associated with a lower awareness of the importance of deworming (p = 0.007), less diligence in administration of deworming (p = 0.004), lower awareness of the risk of acquiring parasites from raw meat (p = 0.010), less likelihood of cooking meat beforefeeding it to their dogs (p =0.028), and less likelihood to properly dispose their dog's faeces (p = 0.027). This study not only indicates a need for improving owner education towards the importance of deworming but also aneed for changing owner's behaviours to reduce potential environmental contamination with infective hookworms. The latter in particular indicates a broader public health risk of disease transmission in public places due to improper disposal of dog faeces, especially in areas with higher canine hookworm infections.

Kei Owada1,Swaid Abdullah2,Nicholas Clark2,Tu Nguyen3, Ricardo J Soares Magalhães14 Zoonoses Public Health. 2023 May 29.doi: 10.1111/zph.13059.

1Queensland Alliance for One Health Sciences, School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.

2School of VeterinaryScience, The University of Queensland, Gatton, Queensland, Australia.

3School of Public Health, The University of Queensland, Herston, Queensland, Australia.

4Children's Health and Environment Program, Children's Health Research Centre, The University of Queensland, Brisbane, Queensland, Australia.

Understanding and treating equine behavioural problems

Behaviour-related issues are common in horses. Many 'undesirable behaviours' pose important safety concerns for the human handlers / riders / carers, as well as welfare concerns for the horse. Undesirable behaviours can also devalue a horse, or result in the horse being re-homed, relinquished, or euthanased. Undesirable behaviours occur for a range of reasons. These include physiological causes, poor management, and the use of inappropriate To page 30

sustainability

Is it time we changed our approach to animal health in low- and middle-income countries?

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“PEXION has provided a vital new tool for the treatment of epilepsy in dogs. As a neurologist, I now use it as my first choice anticonvulsant in drug-naive patients, because of its improved side effect profile over more traditional drugs, its improved hepatic safety, and its short half-life (which means I know whether it’s working fairly quickly). It is also one of the few anticonvulsants that has a sound body of evidence to support its use and it gives us one more option to use in our never-ending quest for that most elusive of things: perfect seizure control.”

– Dr Sam Long BVSc PhD

Eagle Post

Pet health insurance is an intriguing product because it seems comparable to health insurance for people, but the rules governing health insurance are different. Pet insurance is classified as property and casualty insurance. As of 2022, nearly 4.9 million dogs and cats in the US were covered by pet insurance according to the North American Pet Health Insurance Association (NAPHIA). That's only 3 per cent of the US's 150 million dogs and cats, but pet insurance sales have been climbing for at least a decade.

Even as pet ownership booms and health insurance sales for dogs and cats proliferates, most US states have no consumer protection rules specific to pet insurance. Gradually, that is changing. Earlier this year, Mississippi and Washington became the third and fourth states to adopt laws governing pet insurance. The first was in California in 2014, and Maine was next in2022. The laws in Maine, Mississippi and Washington follow a model pet insurance law adopted last August by the National Association ofInsurance Commissioners (NAIC). (California's law, having preceded the NAIC model law, is less rigorous and focused on disclosures). The model requires that insurers make clear disclosures about exclusions; restricts and prohibits waiting periods for specific

Pet health insurance

conditions or circumstances; sharply distinguishes between wellness plans and insurance; and specifies training for people wishing to sell pet insurance. In adopting the model, the NAIC, whose voting members represent the 50 states, the District of Columbia and five US territories, signaled a desire for consistent rules on pet insurance across the country.

As more people began buying policies, complaints followed over issues including fastrising premiums, disagreements about whether acondition is preexisting and extended waits for claims payments. The rise of consumer concerns led states' regulators, working through the NAIC, to push for a uniform approach. The model law gives buyers the right to examine and return a policy for a refund within 15 days. It requires insurers to explain the basis or formula by which claims payments are determined. It prohibits waiting periods for accident coverage and limits waiting periods to 30 days for illnesses or orthopedic conditions not resulting from accidents. Wellness programs cannot be marketed as pet insurance or when pet insurance is being sold, solicited or negotiated.

Along with increased consumer protection, prices for pet insurance are going up, over 50 per cent for some pet owners, due to the demand for veterinary care that insurers say is

fueling higher-than-expected claims costs. The price hikes have at least one prominent insurer bracing for losing customers. For years, owners of veterinary practices have held rising demand for their services on the “humanisation” of pets which are increasingly regarded as family members. Veterinarians have found themselves stretched recently by the COVID pandemic pet boom. At the same time, inflation has been rampant as supplies of goods and services fail to keep pace with pandemic-recovery demand.

The extent to which premium increases are felt across the industry is unclear, as NAPHIA is still collecting 2022 data. Still, the trade group acknowledges that rising demand is pushing up prices for veterinary care and insurance. One insurer has revealed the extent of its pricing changes. Trupanion, one of the biggest publicly listed pet insurers in the US, increased premiums by15 per cent in the first quarter of 2023 and expects them to rise to 18 per cent by year-end. Trupanion expects to lose customers. Still, the price increases will help the company honor its pledge to pay out in claims 71 cents of every dollar it collects in premiums, making its product more attractive eventually.

Pet owners' insurance experience can vary substantially, depending on their pet's age and

low US rate, such as poor initial product design in the US and the immense power of human health insurers there. Despite spiraling premiums and other impediments, insurers are optimistic that US households will become more attracted to pet insurance to cope with the rising cost of care.

Some veterinarians worry that more coverage for pets could boost the industry's influence in setting prices for medical services and make pet insurance as burdensome and controlling as it is for human patients. Veterinarians in Sweden have found that ultra-high insurance coverage levels have improved standards of care, but also pushed up treatment costs. Some veterinarians in Sweden have charged clients an administrative fee to handle processing their insurance claims. Veterinarians in the US are also feeling an increased administrative burden related to insurance. One veterinarian on the Veterinary Information Network (VIN) message boards posted that clients have been asking her to explain what their insurance covers and to write two invoices to separate insured and uninsured procedures. Other clients have asked her to change the name of specific examinations or procedures so their insurance policy will cover them. However, the higher prices have not

breed, the type of policy they bought, and where they live. Social media is strewn with posts from people complaining of extreme rises in their premiums. Dr. Doug Kenney, a retired practitioner in Tennessee who writes a pet insurance blog (https://www.petinsuranceguideus.com), sees prices increasing but notes that isolated upsurges of over 20 per cent for some unlucky customers have been happening for decades, often due to insurers redoing actuarial calculations for certain breeds and zip codes. Kenney writes that the significant increases from one year to the next are usually due to the company's actuaries guessing wrong when setting premiums, or the company rarely updated premiums enough. Age, too, can be associated with substantial price increases, often when pets turn 7 or 8. It means companies are offering lower levels of coverage instead of higher premiums for senior pets. A recent surge in mergers and acquisitions involving pet insurers could also increase prices as takeover deals can trigger a change in an insurance company's underwriter, which could translate to higher customer prices. Pet insurance penetration rates are far higher in a few European countries, especially the United Kingdom and Sweden, where 25 per cent and 65 per cent of pets are insured. Many reasons are offered for the

functioned as a deterrent in her experience. Pet owners need pet insurance," she wrote, “as local specialty hospital prices are excessive at about $2,000 daily for routine cases, and any surgeries are easily in the $10,000 plus range.”

Kenney, the pet insurance blogger in Tennessee, isn't alarmed about pet insurers becoming immensely powerful. He writes that he can see the fear associated with that, but we are a long, long, long way from ever happening, with only 3 per cent penetration. Pet owners seeking pricing flexibility can consider policies that allow them to downgrade terms such as deductibles and reimbursements. For instance, apet owner prepared to pay a higher deductible of, say, $1,000, could get a lower premium in exchange. Setting up a dedicated savings account, as Americans often do for medical costs, might allow pet owners to pay more out-of-pocket and downgrade coverage as needed. He also advises pet owners to pick insurance that covers common conditions that could affect their pets rather than shopping on price. For example, if car insurance were structured like pet insurance, it would be, “Wecover the back half of the car,but we don't cover the front half, and if you want the headlights covered, it's an additional $7.”

Thomas Donnelly, BVSc, DipVP, DipACLAM reports from the US.

Penny has worked extensively in private mixed practice, and in animal biosecurity and welfare for both government and not-for-profit organisations. She manages a 212 hectareDorper sheep breeding property in NSW,and is co-Director ofYour Hobby FarmSuccess, helping hobby farmers enjoy their lifestyle, and reap the benefitsof having healthy and happy animals.

Review of grass tetany

Introduction

Deficiencies in calcium or magnesium are common metabolic disorders seen in cattle, sheep and goats, and can significantly detrimentally affect herds/flocks, especially in cold, rainy seasons. The first widespread cases of grass tetany in a season are often seen after the first spell of cold, wet, windy weather or after heavy frosts.

Milk fever (also known as hypocalcaemia or parturient paresis) is caused by a sudden drop of blood plasma calcium levels near birth, as calcium is required for colostrum and milk.

Grass tetany (also known as hypomagnesemic tetany) is an acute neurological condition caused by low magnesium level in the blood, but it can be complicated by concurrent hypocalcaemia (low blood calcium). Typical clinical signs are excitability, muscle spasms (tetany), convulsions, collapse and death. All ruminants of all ages can be affected (e.g., dairy and beef cattle and sheep) with lactating sheep/cattle grazing rapidly growing green grass or cereal crops that are low in magnesium being most susceptible. It can decimate herds/flocks in cold, rainy weather.

Hypomagnesaemic tetany in calves typically affects two- to four-month-old calves fed milk only or in younger calves with chronic diarrhoea while on milk replacer.Magnesium absorption efficiency in calves being fed with milk falls from 87 per cent at two to three weeks of age to 32 per cent at seven to eight weeks of age. Clinical signs are similar to those seen in grass tetany.

For grass tetany, early treatment with intravenous injection of calcium and magnesium sulphate usually results in rapid recovery, and a subcutaneous injection of magnesium sulphate (200ml of a 50 per cent solution) is also recommended. The affected animal/s should be left in the paddock and not forced to move as any excitation can lead to a poorer outcome, even after treatment. There are several preventative management strategies available including dietary supplementation with magnesium oxide as a topdressing on hay or on pasture.

Epidemiology

Hypomagnesaemia is a global problem, occurring sporadically and affecting up to 10 per cent of a herd. It is a complex, potentially fatal disease and can be a problem anywhere that cool season grasses are a major feed source for cattle and sheep.

Grass tetany is a complex disorder as it may not always arise only from low blood levels of magnesium. Hypomagnesaemia may reflect low magnesium intake or low magnesium absorption or low retention of magnesium, or a combination of all three.

Clinical signs usually develop only when the hypomagnesaemia is accompanied by hypocalcaemia (i.e., blood calcium level below 8mg/dL). There are two recognised designations for grass tetany – a simple form (deficiency of magnesium) and a complex form. There are many contributing factors such as age/breed/lactation

status of the animal, pasture availability and previous/current fertiliser use, stress, and environmental factors.

Magnesium is only stored in small amounts in the bones and muscles (soft tissues), but ruminants cannot readily access and utilise these stores when needed. Animals constantly lose magnesium in milk, urine, faeces and gastrointestinal secretions, so they need magnesium in the feed to meet daily requirements. The large need for magnesium in lactation means that even two days with little or no feed during early lactation, may be sufficient to cause grass tetany. Interference from minerals present in the soil and pasture plants, as well as minerals present in the animals (e.g., sodium, potassium, manganese and chlorine), can influence the amount of magnesium an animal is able to obtain from the available feed.

Grass tetany occurs after a decrease in plasma magnesium concentration when absorption of dietary magnesium is unable to meet the requirements for maintenance (3mg/kg body

aconitic acid in some grass species. Accumulation of trans-aconitate can be a risk factor for hypomagnesemia in grazing ruminants. At least one rumen organism converts transaconitate to acetate, but other rumen organisms convert trans-aconitate to tricarballylate, which complexes with magnesium.

Heavy fertilisation with nitrogen or potassium-rich compounds can interfere with magnesium uptake by pasture plants and high K+/ protein in feed decreases magnesium absorption. Potassium content within grazed plants is an important mechanism in inducing clinical disease. Short pasture of less than 1000kg DM/ha at the one to two leaf stage and more likely to have elevated potassium to magnesium levels, with higher grass tetany risk at this stage of growth.

Lush green grasses are often high in water, and low in calcium and magnesium; the high water content causes rapid transit of food through the gastrointestinal tract and hence,

weight) and lactation (120 mg/kg milk). Magnesium absorption from the rumen may be decreased when potassium and nitrogen intakes are high, and sodium and phosphorus intakes are low Low magnesium plasma level and decreased concentration of magnesium in the cerebrospinal fluid leads to hyperexcitability, muscular spasms, seizures, respiratorydistress, collapse and death.

When grazing heavily fertilised pasture, the high potassium levels can hinder the absorption of magnesium from the rumen. A K/(Ca+Mg) charge ratio exceeding 2.2 in forages is a risk factor for the development of grass tetany. Potassium fertiliser application can contribute to an increased K/(Ca+Mg) ratio in forage plants, by adding potassium to soil and by displacing soil-adsorbed calcium and magnesium by ion exchange, thereby contributing to increased susceptibility of calcium and magnesium to leaching loss from the root zone during rainy seasons. In ruminants, high potassium intake results in reduced absorption of magnesium from the gastrointestinal tract.

Potassium fertiliser application also results in increased concentration of

low uptake of essential minerals. The magnesium content of pastures may be inversely related to high moisture content of grasses (reduces the dry matter and magnesium concentration within the plant). If adequate magnesium is in the soil, plants will develop higher magnesium concentrations as they mature.

Grass tetany is usually seen in autumn and winter,and can occur in all classes of beef cattle, dairycattle and sheep. Older animals pre-calving/lambing or with calves/lambs at foot during winter and spring are most at risk, with non-lactating animals not usually being affected. Dairy cows in peak lactation are most commonly affected, but dry cows and, under certain conditions, beef steers, may also be affected. The incidence of hypomagnesaemia is greatest in high-producing cows in the 3rd to 5th lactation. Older cows may have lower reserves and poorer absorption of magnesium and are not as capable of mobilising magnesium from bone to maintain extracellular fluid magnesium concentrations. Cows greater than five years old in the first three to four months of lactation are more susceptible to grass tetany.

Penny Linnett BSc (Zool Hons) BVSc

MPhil MANZCVS

Body fat is also related to susceptibility with thin to very thin (fat score of 2 or less) or very fat (fat score of 3.5 or more) animals being more susceptible than animals in moderate body condition. Stress, fasting or underfeeding can cause decreases in serum calcium and magnesium levels. Acute exposure to cold, or cold and wet weather without supplemental feeding can result in acute hypomagnesaemia especially in mature pregnant or lactating animals, whereas younger cows/ewes are spared. Angus cattle and their crosses are more susceptible.

Certain dietary factors may interfere with magnesium absorption from the gastrointestinal tract including very high dietary calcium, potassium, phosphate, manganese, sodium and increased fatty acids. In some cases, only 2 per cent of dietary magnesium is absorbed by the animal because of interference from other substances.

Other contributing factors include:

■ Grazing on tetany-prone pastures such as young grass dominant pastures, cereal crops, acid soils and high use of potassium fertilisers. Magnesium levels are lower in cool season grasses and cereals than in legumes or weeds, and levels are low in grasses grown on leached acid sandy soils. Young grasses have low roughage and often poor palatability.

■ Stress – any form can cause an outbreak of grass tetany once the blood magnesium levels are lower than normal. Common stresses are oestrus, mustering, yarding, trucking, feed changes, fasting/starvation and cold weather, particularly storms and sudden drops in temperature (i.e., periods of low energy intake).

Clinical signs

In cows, clinical signs often do not develop until there is hypomagnesaemia and blood calcium concentrations are also reduced (<0.8 mg/dL) which most commonly occurs in cattle grazing green cereal crops. The decreased calcium level arises from either a decrease in calcium intake or absorption or both. Lush green pastures and green cereal crops may predispose cattle tometabolic alkalosis (urine pH >8.5) with a resultant decreased availability of ionised calcium and magnesium; thereby increasing the risk of hypocalcaemia and hypomagnesemia. The magnesium level in urine is a useful guide to magnesium status in the animal. The urine magnesium level becomes undetectable in cows with hypomagnesaemia.

The first sign of a grass tetany outbreak can be simply finding dead cows. Usually there is frothing from the mouth and nose, and there is evidence on the ground of the animal paddling before death. It is possible to miss the early warning signs such as twitching of the face and ears, waryappearance and a stiffened gait. Recovery without treatment once clinical signs occur is unlikely; most cases will worsen and die without treatment.

Affected cows are always excitable and can be dangerous. In mild cases, the only clinical signs may be a change in the animal’scharacter and difficulty in handling. Other mild clinical signs include restlessness, wariness, muscle twitching (facial, flank and shoulders), stiff gait (goosestepping), drooling, frequent urination, and hypersensitivity to touch and sound. This can progress after two to three days (or over a shorter time period if the cow is transported or driven to fresh pasture) to staggering, charging, galloping, bellowing, falling to the ground and paddling with the head stretched back. The animal may have nystagmus and appear to be blind. Animals may be found in lateral recumbency (alive or dead), with or without evidence of paddling or seizure activity. In less severe cases, the only clinical signs may be a change in the animal’s character and difficulty in handling.

When animals have hypocalcaemia and hypomagnesaemia, the resulting clinical signs really depend on which one is predominant.

With hypomagnesaemia, tachycardia (approximately 150 bpm) and loud heart sounds (audible without a stethoscope) are characteristic. High rectal temperatures can occur (up to 45oC) due to excessive muscular activity.

Signs of hypomagnesaemic tetany in sheep occur when hypomagnesaemia (plasma tMg <0.5 mg/dL) occurs concomitantly with hypocalcaemia (plasma tCa <8 mg/dL). The disease in lactating ewes occurs under essentially the same conditions and has the same clinical signs as in cattle. If the animal is down and has survived an attack, any disturbance (especially if touched) may start a new attack of leg paddling. Death may occur within minutes of being seen staggering, especially if driven or stressed in any way.

Diagnosis

Diagnosis is often made on the basis of the clinical signs and history, and usually confirmed by response to treatment, followed by confirmation of hypomagneseamia in samples taken before treatment. Samples submitted for magnesium assay from animals suspected to have hypomagnesaemia include serum, urine, and CSF; samples of vitreous humour (submitted frozen) are recommended for confirmatory testing. For antemortem diagnosis – low total or ionised

■ lead poisoning

■ exotic diseases such as bovine spongiform encephalopathy (BSE) and Aujeszky’s disease, and viruses and bacteria.

Hypomagnesaemic tetany in calves needs to be differentiated from acute lead poisoning, tetanus, strychnine poisoning, polioencephalomalacia, and enterotoxemia due to the toxin of Clostridium perfringens.Analysis of bone aids diagnosis: normal bone has a calcium:magnesium ratio of 70:1; in hypomagnesemic calves, the ratio may be > 90:1.

Treatment

Animals found with clinical signs require prompt/immediate treatment, and ideally the animal should not be disturbed until treatment is initiated. As grass tetany may not always arise from a simple deficiency of magnesium, straight magnesium supplements may be ineffective as the sole treatment. Usually, calcium and magnesium are slowly injected intravenously, often followed by a subcutaneous injection of magnesium.

Magnesium salts are toxic and can result in respiratory failure when given intravenously, so slow administration is recommended and if possible, the heart should be monitored during administration. An intravenous injection given too quickly, or at too large a dose, will kill the cow.

Farmers often have to treat their animals themselves due to the seriousness of the condition. Generally, one to two commercially available plastic packs of calcium and magnesium solution are injected subcutaneously (about 350ml for cattle and 100ml for sheep) followed by 60 to 200 mL of 50 per cent magnesium sulphate solution, also given subcutaneously. By warming the plastic packs to body heat (approximately 38°C) in a bucket of hot water, the solution is made easier to administer, causing less upset to the cow and giving a quicker uptake of calcium and magnesium. Needles should be sterile, and injections into different sites is recommended (e.g., behind the shoulder and over the ribs): the area should be massaged well after administration to help spread the fluid and aid absorption. Repeat treatment may be required.

Follow-up injections of magnesium sulphate (20 to 60 mL of 50 per cent solution) are often required for a day or two. Sixty grams of magnesium oxide – MgO (Causmag®) – should be fed daily after recovery to ensure that the cow’s magnesium requirements are met.

An enema is an alternative treatment is a magnesium-rich enema – 60g MgCl2 6H2O in 250 to 500 ml of warm water. epsom salts diluted in water can also be effective.

serum or urine magnesium concentrations, and postmortem samples – for low CSF or vitreous humour concentrations. Mg concentrations from dead animals may be normal due to muscle damage and leakage from intracellular pools.

Magnesium concentrations < 1 mg/dL (0.4 mmol/L) from the CSF within 12 hours of death or from the vitreous humour of the eye within 24–48 hours after death are indicative of hypomagnesemic tetany, provided environmental temperatures have remained below 23°C.

The reference range for tMg in cattle is 1.8–2.4 mg/dL (0.75–1 mmol/L) and in sheep is 2.2–2.8 mg/dL (0.9–1.15 mmol/L). Tetany usually occurs when plasma tMg is < 1.2 mg/dL (0.5 mmol/L) in cattle and < 0.5 mg/dL (0.2 mmol/L) in sheep. There is often concurrent hypocalcemia. Urine magnesium is usually undetectable in cows with hypomagnesemic tetany.

Differential diagnoses include:

■ staggers caused by phalaris, perennial rye, paspalum and annual ryegrass toxicity nitrate/nitrite poisoning (also seen on young, rapidly growing heavily fertilised grasses and cereals)

The prognosis following treatment is unpredictable, and severe cases (i.e., comatose patients) may still die. Clinical improvement should occur within three to five hours, and the animal should be left undisturbed in a quiet environment during this time. Tranquilisation may be required if convulsions are present and/or severe.

Relapses may occur within three to six hours post-treatment. Exogenously administered magnesium equilibrates slowly across the blood-brain barrier, so as many as 20 per cent of treated cows may die during a convulsion despite treatment. Supplementation with good quality hay (e.g., legume hay) or silage, administration of subcutaneous of magnesium sulphate solution (e.g., 125 to 150 ml of 50 per cent magnesium sulphate solution), and oral magnesium oxide (60g in a gelatin capsule for a cow administered daily for five to six days) can help prevent arelapse.

Sheep can benefit from a slow intravenous infusion of 50 to 150 ml of commercial 5 per cent magnesium preparations that also contain calcium. For calves, intravenous treatment with 125ml of a commercial preparation that is 6per cent magnesium borogluconate.

Other actions that help prevent relapses include increasing energy and roughage intake, adding pellets or grain to the diet (if introduced carefully and the animal/s are already accustomed to these), provide salt if a natural source is not available, providing a magnesium supplement, moving lactating cows/ewes (especially older animals) to high legume and high dry matter pastures, providing shelter and reducing stress for the animal/s (e.g. no yarding, no transport). These actions also play a part in general preventative measures.

Affected animals may not eat, which is a serious complication especially in pregnant ewes which then succumb to pregnancy toxaemia and die.

Hypomagnesmic tetany in calves - affected calves require prompt treatment with a 10 per cent solution of magnesium sulphate (100 mL injected subcutaneously) followed by magnesium oxide at 10 g/day orally. Provision of good-quality legume hay and a starter ration from two weeks ofage helps prevent the disorder.

Prevention

Grass tetany is difficult to treat but relatively easy to prevent with magnesium supplementation. It is important that any supplementation programme ensures that all susceptible animals consume the recommended dose of magnesium.

Prevention with magnesium is by far the best preventative option. Magnesium stored in the body is not immediately available so it must be supplied at least every second day during the period/s of greatest risk. For example, in dairy cows, the greatest risk period is one month before calving to two months post-calving. The provision of hay during periods of lush and rapid grass growth will help reduce the incidence of grass tetany.

Several magnesium feed supplements are readily available from – magnesium chloride, magnesium oxide, magnesium sulphate (epsom salts) and specific grass tetany blocks. Most magnesium salts are unpalatable and need to be combined with other palatable ingredients such as molasses, concentrates, or hay or added to a manufactured pellet with a flavouring agent, or cattle/sheep will sort it out of their feed if they can. Long-term magnesium supplementation prior to grazing tetany-associated pastures has been shown to have little benefit.

Magnesium oxide products can be fed on hay at 60g per head per day for cattle and 10g per sheep per day during the danger period. However, this may need to be increased, and up to 100g per head per day may be needed in cattle. It takes two to three days before stock are protected, and protection stops as soon as the supplementation is stopped. Providing too much Causmag is expensive and can cause diarrhea.

One of the cheapest and most reliable methods of providing magnesium is mixing 600g of magnesium oxide and molasses mixed in two litres of water and poured evenly onto the cut edge of the bale about 12 hours before feeding. This treated hay is fed at the rate of 10 cows or 100 sheep per bale; untreated hay should not be fed out until the ‘treated’ hay has been eaten.

In addition, hay may be treated with this magnesium oxide solution before baling; allowing 600g of magnesium oxide to a ‘bale length’ of windrow. Magnesium oxide may also be added as adrypowder (600 g/bale) during baling, by means of a salting applicator attached to the baler. The treated bales should be stored in a separate stack to allow them to be readily identifiable for use used during danger period/s.

Magnesium oxide may be added to feed fed in the bail at the rate of 45-50g per cow per day but there are indications that levels greater than 30g per cow per day may predispose the cows to Salmonella.

If magnesium is fed over a long period, it is important to add phosphorus (dicalcium phosphate powder or bone flour) as a precautionary

measure because magnesium can reduce the absorption of phosphorus.

The pasture can be dusted with magnesium oxide, preferably applying the powder early in the morning and strip grazing through the week. Herbage may be dusted with powdered magnesium oxide (500 g/cow) or sprayed with a 2 per cent solution of magnesium sulfate at intervals of 1–2 weeks. Redusting may be required if there are heavy rainfalls within 2 to 3 days of dusting; rainfall in the range 25 to 40-50mm. Magnesium oxide can also be sprayed on hay, which is one ofthe cheapest and most reliable methods of providing magnesium supplementation.

Feeding hay alone may be all that is required to prevent hypomagnesemic tetany in herds in which only old cows (>6 years) are affected.

Magnesium blocks are generally not recommended because of their high cost and the difficulty in ensuring that all animals consume enough. However, there are blocks available containing around 16 per cent Causmag®. Variable consumption of looselicks (granulated orpowdered preparations administered from feeders) by cows and sheep leads to insufficient levels of magnesium in some animals. For ewes, 7g of magnesium oxide per head/day can be provided. However, in situations where no more effective means can be employed to deliver the Causmag®, they can be of some use. Follow

The normal water flow should be maintained. The capacity of the trough should be at least nine litres per cow so that the salts are sufficiently diluted. Cattle will scour if they get more than 140g of epsom salts per day. Also, because cattle don't like the taste, the epsom salts need to be added gradually over a two to three week period. So there are several disadvantages in using magnesium salts in stock water, and include epsom salts being unpalatable and not readily accepted by stock. Also, in winter, water consumption is variable due to the high moisture content of the feed and as a result insufficient salts may be ingested.

Inthe longer term, producers should focus on their pastures and soils, as acid soils and high potassium levels are synonymous with occurrence of cases of grass tetany. Fertilizers rich in potassium and nitrogen reduce the availability of magnesium from the pasture, and increase the risk of grass tetany. So avoid grazing these pastures soon after fertiliser application. Pastures can be sampled and tested periodically to determine the levels of potassium, magnesium and nitrogen. If necessary, judicious use of fertilisers to alter the balance is recommended. On acid soils where soil tests show magnesium deficiency, dolomite or magnesium fertilisers can be used.

Other practical management strategies are:

■ Out-wintered stock should be protected from wind and cold and provided with supplementary food. Sheep, cattle and goats should have access to hay, particularly when grazing either green cereal crops or pastures fertilised with potassium or nitrogen (or both).

■ Mustering and transport -- keep to the minimum needed, and avoid transporting animals in the last six weeks of pregnancy.

■ Avoid sudden changes of feed and feed quality – leave the gate open to a fresh paddock so animals can move in and out of the new pasture quietly; they are able to return to their old grazing paddock until they get used to the new pasture.

the manufacturer's instructions concerning the number of cows per block, and when buying blocks ensure that they are recommended for the prevention of grass tetany.

Long-acting magnesium capsules/bullets (about 5cm in diameter, 15cm long and weigh about 250g) delivered down the throat into the rumen provide protection for about 80 to 90 days. They need to be administered at least a week before the high-risk period starts. The release rate is 2 g/day which is only a marginal supplement and therefore, may be of doubtful efficiency.The recommended daily allowance of a cow producing 20 L of milk is 15 g/day. Magnesium bullets may not give sufficient protection when magnesium absorption is being affected by high dietarypotassium. If slow-release intraruminal magnesium devices are used, the animals should also be provided with asource of hay.

Loose licks – granulated or powdered preparations administered from feeders. Magnesium blocks are not considered to be effective, and they are expensive and it is difficult to manage a precise and adequate delivery of the required magnesium for each animal. For ewes, 7g of Mg oxide per head/day can be provided.

Providing soluble magnesium salts in stock water– use of magnesium sulfate (epsom salts) or magnesium chloride in stock water at a rate of 3g/L can be effective. However, this method is not appropriate where surface water is available to cow. This is best done through a Dosatronat arate of 500g per 100 litres of drinking water for epsom salts and 420g per 100 litres of water for magnesium chloride. The salts can also be added at the rate of 60g per cow mixed in 100ml water per day (60g is about two level tablespoons). The dose must be split and added to the water on two occasions during the day.

■ Keep hay for the cows and calves, and ewes and lambs. Let the steers/wethers graze the green crop. The best hay is legume hay because legumes supply nutrients which help reduce grass tetany.

■ Time of calving/lambing/kidding; for example, spring calving cows will be less susceptible than autumn/winter calving cows.

■ Sudden starvation can lead to a reduction of magnesium available to the body system, especially in fat cows and heifers. If you need to reduce body condition score, it should be carried out well before calving/lambing, and not by starving the animal.

■ Any stress on the cow at the critical time may be enough to trigger grass tetany, such as: first oestrus after calving; unnecessary handling and movement; high fat and protein in the diet, which can depress magnesium uptake.

In summary,many factors contribute to grass tetany and it is renowned as being a complex disorder. Good animal management is essential but sometimes, even the best practices are not sufficient to prevent cows/ewes from dying.

Selected references

1. Grass Tetany-Grass Staggers | Department of Natural Resources and Environment Tasmania (nre.tas.gov.au)

2. Hypomagnesemic Tetany in Cattle and Sheep -Metabolic Disorders - MSD Veterinary Manual (msdvetmanual.com)

3. Grass tetany in cattle – treatment and prevention (nsw.gov.au)

4. Milk fever and grass tetany,what’sthe difference? - Local Land Services (nsw.gov.au)

5. Grass Tetany - Stock Sense Fact Sheets (vff.org.au)

6. Grass tetany | Meat & Livestock Australia (mla.com.au)

Characterising circulating nucleosomes in the plasma of dogs with lymphoma

Christopher Dolan1,Tasha Miller1,Jarvis Jill1 ,Jason Terrell2,Theresa Kathleen Kelly2,Thomas Bygott3 and Heather Wilson Robles1

Abstract

Background: Nucleosomes consist of DNA wrapped around a histone octamer core like beads on a string so that DNA can be condensed as chromatin into chromosomes. Diseases such as cancer or inflammation lead to cell death where chromatin is fragmentated and released as mononucleosomes into the blood. The Nu.QTM H3.l assay measures total nucleosome concentration in plasma of humans and has been used to detect and identify cancer even at early stages. The objectives of this study were to determine if nucleosome levels could be used to distinguish between healthy dogs and dogs with various stages of lymphoma (LSA) using the Nu.QTM H3. l assay. Atotal of 126 dogs diagnosed with LSA and 134 healthy controls were recruited for this study. Plasma was collected from each dog and stored in K2 EDTA tubes. The LSA patient samples were recruited

Background

Liquid biopsy is a growing field in human medicine and has significant potential in veterinary medicine as it enables the use of minimally invasive techniques and analysis of tumorderived material including circulating tumor cells, extracellular vesicles, and cell free DNA, among others. Information provided through these tools in cancer patients can provide early detection of neoplastic disease, provide prognostic information, monitor response to treatment, and help identify druggable targets (1, 2]. Furthermore, liquid biopsy assays are much more amenable to serial testing when compared to traditional tissue biopsies or expensive imaging tests.

Nucleosomes are the basic repeating subunit of chromatin consisting of DNA wrapped around a histone core [3]. Nucleosomes regulate several important functions within the cell in part due to a complex network of modifications and regulator y enzymes that control their positioning and stability.Due to the variety and flexibility of modifications, nucleosomes provide the framework for chromatin assembly, epigenetic regulatory mechanisms, while also protecting DNA from damaging agents [4].

Cell free DNA is released into the bloodstream, as nucleosomes, from a variety of cell types that are undergoing apoptosis or necrosis but are most commonly released from hematopoietic cells as part of normal cellular turnover [5–7]. Low levels of cfDNA have been identified in healthy individuals and increased concentrations are present during various disease processes [8]. Nucleosomes have been shown to have different immunostimulator y potential as compared to circulating free histones and cfDNA [9]. Therefore, while these circulating components are related and share similar origins, they should be considered distinct entities with potentially different functions. Nucleosomes are elevated in humans and dogs with significant inflammation and increased nucleosome concentrations have been shown to be prognostic for survival in dogs experiencing trauma [10–12]. In neoplastic disease processes, nucleosomes are elevated in human patients with colorectal cancer and could help with early detection of this disease [13]. Nucleosomes have also been able to predict response to therapy in patients with advanced non-small-cell lung cancer [14]. Similarly, cfDNA levels are elevated in dogs with various tumor types and cfDNA levels correlated well with clinical stage [15, 16]. While nucleosomes themselves have not been extensively evaluated in canine neoplastic

from TAMU or purchased from various biobanks. All control cases were recruited from TAMU.

Results: Dogs with LSA had an approximately 7-fold increase in their plasma nucleosome concentrations compared to controls (AUC 87.8 per cent). Nucleosome concentrations increased with cancer stage and dogs with B cell lymphomas had significantly higher nucleosome concentrations than dogs with T cell lymphomas.

Conclusions: The Nu.QTM H3. l assay was able to reliably detect elevated nucleosome concentrations in the plasma of dogs with LSA. Furthermore, it appears that nucleosomes are useful for differentiating cancer from healthy individuals in canines.

Keywords: Canine, Lymphoma, Circulating nucleosomes, Cell free DNA, Circulating DNA, Histone 3.1

disease, a recent study did show significantly elevated nucleosome concentrations in a small cohort of dogs diagnosed with lymphoma (LSA) [17].

Lymphoma is one of the most frequently diagnosed cancers in the dog and multicentric LSA, characterized by peripheral lymph node enlargement, is the most common clinical presentation of this disease [18]. Often, patients are diagnosed with higher stage disease due to the fact that pet owners often have to recognize the lymph node enlargement before these pets are presented to a veterinarian for diagnosis [19]. The response to therapy for this disease is typically determined by serial measurements of peripheral lymph nodes. Inter- and intra-rater reliability of these measurements are reported to be good to excellent in the clinical setting [20]. Lymph node measurements are helpful in establishing the initial response to therapy evidenced by lymph nodes decreasing in size as well as determining disease progression when the lymph nodes increase in size following therapy. Monitoring peripheral lymph nodes as the primary indicator of treatment response is lacking as it does not detect minimal residual disease (MRD) after the lymph nodes have returned to a normal size. Previous studies in both humans and dogs have shown a variable amount of MRD following a positive response to therapy and the level of MRD at the end of achemotherapy protocol has been shown to be prognostic [21, 22]. Lymph node measurements also fail to detect early indicators of disease progression as the disease burden must advance enough to cause lymph node enlargement before the patient is determined to be out of remission. Establishing liquid biopsy techniques, such as measuring nucleosome levels, in canine lymphoma could be helpful by providing objective measures of disease progression or treatment response even if the lymph nodes are normal in size. Such techniques could potentially reveal the MRD as well as provide an early indication of progressive disease prior to detectable lymph node enlargement.

The Nu.QTM H3.1 Assay detects circulating nucleosomes in the blood of humans that occur with various disease states and has been used to detect and identify cancer even at early stages [13, 23]. This platform is an enzyme-linked immunosorbent assay (ELISA) directed at the histone H3.1 (H3.1) core histone protein. Previous investigations with histone H3.1 have identified cancer-associated mutations which induced nucleosome instability and enhanced cancer cell colony formation [24].

The objectives of this study were to determine whether H3.1 nucleosome concentrations could be used to distinguish healthy dogs and dogs with of LSA using the Nu.Q H3.1 assay as well as how nucleosome levels varied across disease stage and immunophenotype.

Results

Patient population

Atotal of 260 dogs were included in this study with 134 in the healthy control cohort and 126 in the LSA cohort. All healthy dogs and 10 dogs with lymphoma were recruited from the Texas A&M University Veterinary Medical Teaching Hospital (TAMU VMTH). The remaining 116 lymphoma samples were collected from the National Cancer Institute Division of Cancer Treatment and Diagnosis (NCI-DCTD) Canine Tumor Repositoryand represented 8 different collection sites. Information regarding the number of cases collected at each site along with number of cases per stage and immunophenotype are provided in Table 1. The healthy control cohort ranged in age from 0.83 to 14 years (median 6 years) and the LSA cohort ranged from 2 to 15 years (median 9 years). The healthy control cohort ranged in weight from 2.5 to 55.8 kg (median 23 kg) and the LSA cohort ranged from 5.0 to 74.5 kg (median 28.8 kg). The breeds most prevalent in the healthy control cohort were mixed breed (n = 29), Labrador retriever (n = 15), Australian cattle dog (n = 10), pit bull terrier (n = 7), border collie (n = 6), golden retriever (n = 5), dachshund (n = 4), and German shepherd (n = 3). The breeds most prevalent in the LSA population were mixed breed (n = 39), Labrador retriever (n = 10), cocker spaniel (n = 4), golden retriever (n = 8), Shetland sheepdog (n = 4), giant schnauzer (n = 3), and 2or fewer of a variety of other pure bred dogs such as German Shepherd dogs, boxers, Basset Hounds and terriers. The healthy control cohort had a male to female ratio of 1.05 and a sex distribution including 4 intact females, spayed females (n = 61), intact males (n = 3), and castrated males (n = 65). Comparisons were made within the healthy cohort for age, body weight and gender and no statistical difference was found in between any of the groups (data not shown) [25]. The LSA cohort had a male to female ratio of 1.86 (82 males and 44 females) and a sex distribution including intact females (n = 3), spayed females (n = 41), intact males (n = 9), and castrated males (n = 73).

Clinical Review

Nucleosome concentration

The nucleosome concentrations in the LSA cohort (median 211.1 ng/ml, mean 570.9 ng/mL, SEM 90.85, range 0–6544 ng/mL) were significantly higher than those in the healthy control cohort (median 31.1 ng/ml, mean 32.07 ng/mL, SEM 1.118, range 0–67.42 ng/mL) with a p-value of < 0.0001 (Fig. 1). According to the receiver operator characteristic (ROC) curve the area under the curve was 87.8 per cent with a sensitivity of 80.16 per cent and a specificity of 94.78 per cent with a cut off for the healthy range set at 67.5 ng/mL (nucleosome range for all healthy dogs was 6.33–67.42 ng/mL).

Comparisons were made between nucleosome concentrations for LSA patients from each collection site. The median nucleosome concentration for samples collected at TAMU-VMTH was 429.5 ng/ml (n = 10, mean 818 ng/ml, SEM 198, range 32.2–4218 ng/ml), at collection site 1 was 219.3 ng/ml (n = 18, mean 495.1 ng/ml, SEM 188.5, range 0–2689 ng/ml), at collection site 2 was 154.8 ng/ml (n = 11, mean 597.8, SEM 284, range 38.1–2450 ng/ml), at collection site 3 was 164.4 ng/ml (n = 22, mean 604 ng/ml, SEM 188.4, range 0–2451 ng/ml), at collection site 4 was 247.3 (n = 20, mean 535.8 ng/ml, SEM 150.9, range 23.3–2450 ng/ml), at collection site 6was 193.8 ng/ml (n = 23, mean 193.8, SEM 61.9, range 0–958.5 ng/ml), and at collection site 8 was 177.4 ng/ml (n = 17, mean 421.3, SEM 121.6, range 19.5–1730 ng/ml). Collection sites 5and 7 did not have sufficient case numbers for meaningful comparisons (6 and 2 cases, respectively). No significant differences were found for nucleosome concentration between collection sites with the p-value for all comparisons > 0.999. Nucleosome concentrations were evaluated in LSA patients to determine if they were affected by age, gender, or body weight. Information for sex was available for all LSA dogs and information for age and body weight were available for

Mean plasma nucleosome concentrations (ng/mL) were significantly higher in LSA dogs compared to healthy controls. Boxes represent the mean and the bars represent the standard deviation. Dots represent individual data points. **** indicates a p value < 0.0001

120 LSA dogs. LSA dogs were split into 3 age groups (1–5 years n = 27, 6–10 years n = 70, and >10 years n = 23). There were no statistically significant differences in nucleosome concentration among the different age groups (Table 2). Dogs with LSA were split into 4 different groups based on gender (female spayed n = 41, female intact n = 3, male neutered n = 73, and male intact n = 9) and no statistically significant differences were found between these groups (Table 3). Finally,the LSA dogs were split into 4groups based on body weight (< 15 kg n = 29, 15–30 kg n = 41, 31–45 kg n = 41, and > 45 kg n = 9).

No statistically significant differences were identified between different body weight groups (Table 4).

To determine whether nucleosome concentrations were elevated across all stages of LSA, we compared nucleosome concentrations between healthy controls and the different stages of lymphoma. Stage of disease was available for all patients included in this study.All stages of LSA, except stage II, had significantly elevated nucleosome concentrations compared to healthy controls (Fig. 2). The median nucleosome concentration for stage I LSA was 104.9 ng/ml (n = 11, mean 691.9 ng/ml, SEM 358, p-value 0.0002, AUC 87.99 per cent), for stage II LSA was 36.2 ng/ml (n = 7, mean 135.6 ng/ml, SEM 96.45, p-value >0.088, AUC 69.2 per cent), for stage III LSA was 177.5 ng/ml (n = 37, mean 452.9 ng/ml, SEM 130.4, p-value < 0.0001, AUC 85.1 per cent), for stage IV LSA was 200.2 ng/ml (n = 38, mean 564.2 ng/ml,å SEM 167.9, p-value <0.0001, AUC 91.7 per cent), and for stage V LSA was 421.4 ng/ml (n = 33, mean 763.0 ng/mL, SEM 217.7, p-value < 0.0001, AUC 90.3 per cent).

We next investigated whether elevated nucleosome concentrations were common to both B-cell and T-cell LSA. Immunophenotyping information was available for 61 LSA cases, and nucleosome concentration was compared amongst two immunophenotype groups and healthy controls. Nucleosome concentrations were significantly elevated in both B-cell and T-cell LSA compared to healthy controls (Fig. 3). The median nucleosome concentration for B-cell LSA was 421.42 ng/ml (n = 43, mean 1031.7 ng/ml, SEM 234.2, p-value < 0.0001, AUC 98 per cent) and 153.7 ng/ml for T-cell LSA (n =18, mean 277.6 ng/ml, SEM 99.4 p-value 0.0006, AUC 74.9 per cent). T-cell LSA patients were found to have a significantly lower nucleosome concentration than B-cell LSA

Table 1. Number of cases per stage and immunophenotype for each collection site

Fig. 1. Elevated Nucleosome Levels in LSA.

patients (p-value 0.018). In the B cell lymphoma cohort there was one dog with WHO stage I disease (2.3 per cent), no dogs with stage II disease, 13dogs with stage III disease (30.2 per cent) and 15 dogs each with stage IV (34.9 per cent) and 14 with stage V disease (32.6 per cent). For the Tcell lymphoma cohort there were no dogs with stage I disease, one dog with stage II disease (5.6 per cent), 10 dogs with stage III disease (55.6 per cent), 2 dogs with stage IV disease (11.1 per cent) and 5 dogs with stage V disease (27.8 per cent). When using the compressed WHO staging system previously published by Valli et al. in 2013, the two have a similar distribution of stage with compressed stage 1 (stages I/II) including one dog each (B cell 2.3 per cent and T cell 5.5 per cent), stage 2 (compressed stages III/IV) the B cell cohort had 28cases (65.1 per cent) and the T cell cohort had 12 cases (66.6 per cent), finally for the compressed stage 3 (stage V) the B cell cohort had 14 (32.5 per cent) cases and the T cell cohort had 5cases (27.8 per cent) [19].

A receiver operating characteristic analysis was performed with an established threshold of67.4 ng/ml which generated an area under the curve of 0.878 (Fig. 4).

This threshold produced a sensitivity of 74per cent at a specificity of 100 per cent. The performance of this threshold for each specific stage was investigated by applying it retroactively to the population of LSA patients. This analysis showed that the threshold could accurately distinguish LSA patients from healthy patients in 63 per cent (7/11) of stage I patients, 14.3 per cent (1/7) of stage II patients, 75.7 per cent(28/37) of stage III patients, 81.6 per cent (31/38) of stage IV patients, and 81.8 per cent (27/33) of stage V patients. Perform-ance was also evaluated by immunophenotype and the threshold could distinguish LSA patients from healthy patients in 95.3 per cent (41/43) of B-cell LSA and 55.6 per cent (10/ 18) of T-cell LSA.

Discussion

The current study follows from previous findings in which nucleosome levels helped with early detection of cancer in humans and were significantly elevated in a small cohort of dogs with LSA [13, 17]. As with most studies, there were limitations present in this study. Samples received from the DCTD Canine Tumor Repository had variable amounts of patient demographic, staging, treatment and outcome data available which would have been useful in generating more power for the analysis and better characterization of those cases with low stage disease and T cell phenotypes. Additionally, the samples derived from the DCTD Canine Tumor Repository had been stored much longer than those collected from TAMU, potentially up to 5 years or more. Though not statistically different, the TAMU lymphoma cases (n = 10) had higher plasma nucleosome concentrations than those collected from the biobank. A study by Holdenrieder et al. determined that there is some loss over time of nucleosomes in EDTA stabilized serum samples that is slightly less than 7 per cent per year [26]. This likely explains the differences in the median concentrations from those collected at TAMU and those from the biobank. However, all healthy canine samples were also collected prospectively at TAMU and stored for less than 6months. The lack of variability and low median and mean plasma concentrations in the 134 healthy dog samples regardless of age, body weight or gender (median 31.1 ng/ml, mean 32.07 ng/mL, SEM 1.118, range 0–67.42 ng/mL) adds credence to the utility of this test to discriminate between healthy dogs and those with lymphoma. Additionally, it is possible that the reported sensitivity is lower than what it is actually true for this test if there was loss of nucleosomes in storage. Shorter storage times may have resulted in a larger difference between

Fig.

concentrations (ng/mL) in all LSA stages (except stage II) were significantly higher than healthy controls. Boxes represent the mean and the bars represent the standard deviation. Dots represent individual data points. *** indicate a p value < 0.001, **** indicate a p value < 0.0001

the healthy and LSA cohorts, and, subsequently, an improved discrimination between the two groups than what was reported in this study. Lastly, the healthy control population was screened with a physical examination and questionnaire regarding the pet’s health status. Biochemical analysis such as a complete blood count, serum biochemistry,and urinalysis were not performed on this population, and it is possible that an underlying silent disease process may not have been discovered during healthy patient evaluation.

As previously described by this group in a small cohort of dogs with lymphoma, nucleosome concentrations were significantly elevated in the cohort of LSA patients when compared to the healthy control cohort [17]. The median plasma nucleosome concentration in LSA patients was 6.8 times higher than in the healthy controls. Broadly we found that elevated nucleosome concentrations were present at all cancer stages, except stage II, and present in both B and T cell lymphoma. There were no significant differences found when comparing

Table 2. Nucleosome concentrations in dogs with lymphoma separated by age

Table 3. Nucleosome concentrations in dogs with lymphoma separated by gender

Table 4. Nucleosome concentrations in dogs with lymphoma separated by body weight

2. Mean Nucleosome Concentrations: LSA by Stage. Mean plasma nucleosome

nucleosome concentrations in lymphoma patients by age, gender, or body weight groups.

When evaluated by stage, only the dogs with stage II LSA were found to not have significant elevations compared to healthy controls. This subpopulation contained only 7 dogs and the lack of significance is suspected to be due to a population of insufficient size. This was supported by a post-hoc power analysis with an alpha set at0.05 and a power set at 80 per cent which indicated that a minimum of 16 cases would be needed to effectively evaluate this group. Another potential consideration is that the tumor burden associated with this stage of disease does not produce more nucleosomes than healthy dogs. However, this is unlikely since the nucleosome concentrations of dogs diagnosed with stage I LSA were significantly elevated compared to healthy controls in this study. Another consideration for the low nucleosome concentration in the stage II LSA cases is aTcell phenotype. The dogs in this study with Tcell LSA had significantly lower nucleosome concentrations than those with B cell LSA, however, upon further review, only one of the dogs with stage II LSA had immunophenotype data available and this dog did, indeed, have T cell LSA. Additional collection and analysis of lower stage LSA patients with full characterization of their disease is needed to help further characterize the nucleosome concentrations in these patient populations.

When evaluated by stage, only the dogs with stage II LSA were found to not have significant elevations compared to healthy controls. This subpopulation contained only 7 dogs and the lack of significance is suspected to be due to a population of insufficient size. This was supported by a post-hoc power analysis with an alpha set at 0.05 and a power set at 80 per cent which indicated that a minimum of 16 cases would be needed to effectively evaluate this group. Another potential consideration is that the tumor burden associated with this stage of disease does not produce more nucleosomes than healthy dogs. However, this is unlikely since the nucleosome concentrations of dogs diagnosed with stage I LSA were significantly elevated compared to healthy controls in this study. Another consideration for the low nucleosome concentration in the stage II LSA cases is a T cell phenotype. The dogs in this study with T cell LSA had significantly lower nucleosome concentrations than those with B cell LSA, however, upon further review, only one of the dogs with stage II LSA had immunophenotype data available and this dog did, indeed, have T cell LSA. Additional collection and analysis of lower stage LSA patients with full characterization of their disease is needed to help further characterize the nucleosome concentrations in these patient populations. As mentioned above, while both B-cell and T-cell LSA had significant increases in nucleosome concentration compared to healthy controls, B-cell LSA patients had a 2.7 fold higher median nucleosome concentration as compared to T-cell LSA patients. The underlying mechanism ofthis difference is unknown. One potential explanation is that while T-cell LSA patients often have peripheral lymphadenopathy,it is the authors’ experience that their disease burden is subjectively lower than their B-cell counterparts in the clinical setting. The lower nucleosome concentration detected in this study may be the result of an overall lower disease burden that occurs between B-cell and T-cell LSA. In humans, it has been shown that the amount of cfDNA shed by a LSA patient depends on the particular LSA subtype [27]. It is possible this is also true in dogs and the difference between B-cell and T-cell LSA nucleosome concentrations are indicative of underlying pathophysiologic differences between these LSA subtypes. Finally, owing to the fact that many samples for the lymphoma cohort were purchased from a biobank, most of the cases in this population were not

Fig.

Mean Nucleosome Concentrations: LSA by Immunophenotype. Mean plasma nucleosome concentrations (ng/mL) in B and T cell LSA were significantly higher than healthy controls. B cell LSA mean nucleosome concentrations were significantly higher than T cell LSA. Boxes represent the mean and the bars represent the standard deviation. Dots represent individual data points ** indicate a p value < 0.01, **** indicate a p value < 0.0001

characterized by flow cytometry. It is possible that some of the samples in this group were from dogs with indolent T-cell LSA. Standard immunophenotyping (CD3 positivity) would not be able to differentiate the less aggressive T-cell lymphomas from the more aggressive T cell lymphomas. Studies in humans have also shown that the levels of cfDNA are higher in more aggressive subtypes of LSA [27, 28]. If indolent LSA cases were included in the population of T-cell LSA cases, they may have artificially lowered the overall nucleosome concentration in this population.

Asensitivity of 80.16 per cent at a specificity of 94.78 per cent in distinguishing LSA patients from healthy controls was achieved using nucleosome concentrations with a threshold of 67.5 ng/ml. This indicates that nucleosomes could be auseful screening tool in the differentiation of dogs with LSA from healthy dogs. The ROC curve demonstrated that some cases of LSA fell below the discrimination line. These cases were of lower stage or had a T cell phenotype and had plasma nucleosome concentrations similar to the healthy control cohort. This is to be expected as nucleosome concentrations are correlated with stage and, therefore, tumor burden in humans [13, 29, 30]. Similar results were found in the dogs evaluated in this study where the nucleosome concentration increased with stage and tumor burden. Despite this finding, the established threshold was successful in discriminating 63.6 per cent of stage 1 LSA patients from healthy controls. This is an encouraging finding as it shows that circulating nucleosomes could be used as a tool for early disease detection and could be helpful when a diagnosis is difficult to establish.

Conclusion

The results of this study demonstrate that plasma nucleosome concentrations of dogs with LSA are significantly elevated compared to healthy controls. These findings support the use of nucleosomes as a tool for the early detection ofLSA in dogs.

Methods

Healthy dogs

Dogs were recruited from patients presenting to the TAMU VMTH for routine wellness exams or from dogs owned by TAMU VMTH personnel.

All animal studies were approved by the Texas A&M University Animal Care and Use Committee (AUP #2017–0350). Owners were questioned to determine the health status of each patient and a physical exam was performed at the time of sample collection. In order to be eligible for inclusion, dogs were required to be over one year of age and healthy. Dogs were excluded if there was any secondary significant inflammatory/infectious disease or previous diagnosis of neoplasia. A disease was considered significant if the dog was currently undergoing therapy or if the disease was expected to alter the dog’ssurvival. Dogs were allowed to participate if they were on joint supplements, flea and tick preventative and/or heart worm prevention. Information recorded for each patient included signalment, body weight, body condition score, and any relevant comorbidities reported by the owner.

Lymphoma dogs

The LSA dog cohort was recruited in part from dogs presenting to the TAMU VMTH for treatment of naive multicentric LSA (AUP #2019–0211). For the TAMU VMTH patients, the diagnosis of lymphoma was made either through the use of lymph node cytology, flow cytometry, or a combination of these techniques. The remaining samples were recruited from the National Cancer Institute Division of Cancer Treatment and Diagnosis (NCI-DCTD) Canine Tumor Repository. Samples provided to the NCI-DCTD were collected prior to the initiation of therapy,and were confirmed to be lymphoma via histopathology, immunophenotyping data, and/or cytologic diagnosis provided to the repository.

When available, information including patient signalment, body weight, body condition score, stage of disease, and immunophenotype were recorded.

Sample collection and processing

For patients presenting to the TAMU VMTH, 3–5 mLs of blood was collected from dogs fasted at least 6 h before collection and immediately placed in K2-EDTA blood collection tubes. Within one hour of collection, samples were centrifuged at room temperature at 3000xg for 10 min. Plasma was then immediately removed without disrupting the buffy coat layer, placed in

3.

Fig. 4. Discriminating LSA from Healthy Controls. ROC analysis with an established threshold of 67.5 ng/ml generated an area under the curve of 0.878. This threshold produced a sensitivity of 80.16 per cent at a specificity of 94.78 per cent

pre-labeled cryovials and frozen at – 80°C to run in batches. Processing samples with this protocol was shown to be appropriate for reliable, consistent nucleosome detection in dog plasma [17]. Samples received from the DCTD Canine Tumor Repository were stored frozen at – 80°C to be run in batches. For these collections, approximately 25 – 30 mLs of blood and 2–3 mLs of urine were collected before surgical excision or biopsy of treatment naïve tumor tissue. Body fluids were processed and stored at – 80°C within one hour of collection. The initial centrifugation and storage requirements were in line with what is required by the assay. Plasma samples stored at – 80°C for DNA analysis have been shown to be stable for more than 10 years and nucleosomes concentrations in EDTA stabilized serum samples have been shown to have minimal loss (< 7 per cent per year) after long term storage (> 60 months) [26, 31].

Nucleosome assays

Frozen samples were thawed and allowed to come to room temperature for at least 30 min prior to analysis. All samples were performed in duplicate. The samples were evaluated using the Nu.QTM H3.1 ELISA (Belgian Volition, SRL, Isnes, Belgium) and were performed according to the manufacturer’s instructions. Briefly, a standard curve was generated using the known standards provided. Before use, the wells were washed 3 times with 200µL of the provided diluted wash solution with excess solution being removed after each wash. Patient and healthy dog plasma samples were vortexed and then centrifuged for 2 min at 11,000xg at 4°C before samples were loaded into the plates. Lymphoma samples were diluted 3-fold in order to ensure that they would register on the plates within the limits of the colorimetric standards. Twenty microliters of patient samples and kit controls were run in duplicate in wells on 96 well plates. Eighty microliters of assay buffer was then added to each well. The plates were sealed with foil and incubated at room temperature for 2.5 h under agitation at ~ 700 rpm. Plates were emptied and washed as described above. Next, 100 ìL of HRP labelled detection antibody was added to each well. The plate was sealed with foil and incubated at room temperature for 1.5 h under agitation at ~ 700 rpm. Plates were then emptied and washed as described above. Next, 100µLofTMB substrate was added to each well. The plate was sealed with foil and incubated at room temperature for 20 min in the dark under agitation at ~ 700 rpm. One hundred microliters of stop solution were then added and the plate was shaken gently.Plates were read at an absorbance of 450 nm (BioTek Synergy H1 plate reader,

BioTek Instruments, Winooski, VT) within 5 min of stop solution be-ing added. The standard curve was linearized and fitted to a 5-parameter logistic curve using statistical software (Graphpad Software, version 8, San Diego, CA).

Statistical analysis

Descriptive statistics for the patient populations were performed using Microsoft Excel for Mac (v. 16.16.27, 2016). For data sets containing only two cohorts, such as the healthy controls versus all LSA cases, a Wilcoxon rank sum test was used to compare the medians of the data sets. For data sets where multiple conditions were compared such as disease stage, a two-way ANOVA for repeat measures with a Tukey’s multiple comparisons test was performed. This part of the analysis was performed using GraphPad Prism version 8.0.0 for Macintosh, GraphPad Software, San Diego, California USA, www.graphpad.com. Spearman’s correlation, ROC curves and specificity/sensitivity calculations were performed using R version 3.4.3 and the pROC package [32, 33].

Abbreviations

LSA: Lymphoma; TAMU VMTH: Texas A&M University Veterinary Medical Teaching Hospital; ROC: Receiver Operating Characteristic; MRD: Minimal Residual Disease.

Acknowledgements

This article was supplied by Heska and previously appeared in BMC Veterinary.

Author details

Small Animal Clinical Sciences Department, Texas A&M University, College of Veterinary Medicine, College Station, TX 77843, USA. Volition America LLC, 13215 Bee Cave Parkway, Galleria Oaks B, Suite 125, Austin, TX 78738, USA. Volition Diagnostics UK Ltd, 93 95 Gloucester Place, London W1U 6JQ, UK.

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Connection is key to mental wellbeing

Increasing interest rates, inflation, rising living costs and concerns about the future are among the primary causes of community concern for people living in regional Australia, according to a new survey by Beyond Blue. However, despite the importance of seeking help for mental health, many Australians are hesitant to do so, especially in rural areas where there is a stigma surrounding mental illness.

Research shows that being connected to others is crucial for mental wellbeing and can serve as aprotective factor against anxiety and depression. Zoetis, the leading animal health business, has partnered with Beyond Blue for seven years to support mental health initiatives and reduce stigma around mental illness in rural and regional Australia. During this time, Zoetis raised $700,000 for the Beyond Blue Support Service by donating $5from each sale of the company’s livestock, pig, and poultry vaccines and drenches. In 2023, Zoetis has set a goal to raise an additional $100,000 by the end of the year.

“Zoetis works closely with rural Australia through interactions with the country’s farming community, agricultural stores, veterinarians and their families,” Lance Williams, Zoetis Senior Vice President and Cluster Lead, Australia and New Zealand, said. “We are proud to once again be supporting Beyond Blue and the important work they do.”

“The farming community has endured many challenges over the years. Through economic insecurity, social isolation, loneliness, and insecure work, we’re seeing an increase in many of the factors that drive mental health challenges. Rural Australia and countrypeople are stoic and display considerable courage, however, the impact on mental health has been significant for many.”

“Social connections are closely tied to our physical and mental wellbeing. Feeling connected with others can reduce stress and build resilience. Having someone to talk to and support you is important,” Patrice O’Brien, Beyond Blue Chief Community Officer, said. “People in rural Australia are known for their resilience in times of crisis, but even the most resilient need extra support at times. Timely diagnosis, treatment, and ongoing management of a mental health condition in rural areas are likely to occur later or not at all, often resulting in an increased probability of the most tragic of outcomes. We want everyone to know that support is available.”

The journey to better mental health can start with small actions. “It’simportant to make looking after ourselves a priority. Maintaining social connections, keeping in touch with friends and family,and being part of a

community provides a supportive network. Also, understanding which tools and strategies work well for you in tough times and reaching out for that extra support when you need it are really important,” O’Brien said.

“You are not alone, and you don’t have to work things out by yourself,” O’Brien said. “Seeking support at the first sign you’re not feeling quite yourself can make it easier to bounce back and maintain good mental health. Sometimes, just talking to someone can make a difference.”

People can support the Zoetis initiative between July 15 and October 31. For each sale of the company’s livestock, pig and poultry vaccines and drenches Zoetis, will donate $ 5, up to $100,000, to Beyond Blue.

“The money raised goes directly to the Beyond Blue Support Service to continue helping people living in remote areas,” Williams said. “To date, thanks to Zoetis’s donation, over 14,000 people have been able to get the support they need through the service. Together we have made strong progress in supporting the mental health and wellbeing of those who live in rural Australia, and we are passionate about helping again this year.”

For more information on how you can help Zoetis to raise vital funds to support mental health in rural communities through its partnership with Beyond Blue please visit www.zoetis.com.au. For more information about depression and anxiety, visit www.beyondblue.org.au. The Beyond Blue Support Service offers free and immediate counselling, advice and referrals via phone, webchat or email. To talk to a mental health professional for free, contact the 24/7 Beyond Blue SupportService on 1300 22 46 36. Free web chat is also available 24/7 at beyondblue.org. au/support-service/chat and you can join the website’s online forums for free.

CASE STUDIES

Here, some Beyond Blue community speakers share personal stories of resilience, and how they have been supported in their steps to better mental health.

John Clark: Harford, Tasmania

John Clark, a former chemical engineer, was once so ashamed of his suicidal state that it took him five months to work up the courage to fill a script for medication after he was diagnosed with major depression. More than adecade later, the father of three prevents suicide through his work speaking about depression and anxiety with men in rural Tasmania.

“I couldn't talk about my feelings because tough guys don't have feelings, and even if we did have feelings, we wouldn't talk about them,” John says. “That meant getting help was out of reach for me. I continued to deteriorate and eventually caved in and went to the doctor, just full of shame and feelings of failure.”

This was the start of John’s recovery journey. He left the management job that had led to burnout and started spending more time with his children, improving his home life. Along with speaking to apsychologist, he took up hobbies, began exercising in nature and got back to his roots – working on a farm and with his hands. But the main contributor to John’swellbeing has been helping others, including as a mental health support and suicide prevention worker Not long ago, he suggested a miner get assessed for PTSD after being injured in a pub fight. The miner’s niece later told John that this advice had turned the miner’s life around and asked John to speak to her workplace through his new organisation Industry Minds. “You can make such a huge difference with just a short conversation,” John says. “I've found that vulnerability, being able to be authentic, transparent, open and talk about my emotions, to be really empowering. It's one of the secrets to getting better again.”

Rachael Kobold: Coffs Harbour, New South Wales

along the NSW coast. “I ended up starting up a women's social group to try and counteract my feelings of loneliness and build a friendship base,” she says. “Having seen that grown substantially and watching the benefits for other women has been amazing. Connections are super important for me, and for rural communities as a whole.”

Rachael had her first experience with mental ill health at just eightyears-old, but she had no idea what was happening to her. Her mother took her to the GP who misdiagnosed her with lactose intolerance. She ended up in and out of hospital, having all multitude of scans and tests for physical ailments, until she read about anxiety in a textbook in her mid-teens. Her anxiety progressed to panic attacks, which prompted her to find an understanding GP, who gave her referral to a psychologist in her early 20s.

“We talked through what I was going through and a lot of it was alleviated just by finally getting it off my chest,” Rachael, who was diagnosed with generalised anxiety disorder, says. Life stressors cause her anxiety and depression to flare up, and she was later also diagnosed with ADHD and a panic disorder. Now aged 28 and living on the mid north NSW coast, Rachael is motivated to share her experience as she doesn’twant others to have to wait so long to get help like she did.

Garry and Shirley Semmens: GoulburnValley, Victoria

Rachael Kobold, a business development manager who grew up on the far south coast of NSW, found living in rural communities with a mental health condition an isolating experience. She longed for connection. Rachael guessed she wouldn’t be the only one, so she launched a support group four years ago that now has almost 900 members across two locations

Along with sharing their lives together, husband and wife Garry and Shirley Semmens share a passion for helping others overcome mental ill health. The couple, who live in regional Victoria, were both inspired into careers supporting others after experiencing anxiety and depression themselves.

Garry, a retired drug and alcohol counsellor, had three breakdowns in his younger years, mostly related to work stress and a relationship breakdown. His mental health improved after taking medication, speaking to a psychologist and learning what brings him joy. Through his work, he has learnt the key to good mental health is hope. “If you can instil hope in someone, you've got agood chance of moving them forward,” he says.

Meanwhile, Shirley, a semiretired community services and counselling trainer, went through significant grief and loss To page 30

Evolving to co-exist Australian ecologist wins US Quest Award

From page 5 to be vital due to uncertainties around the species’ future, and whether the evolutionary dynamics that apply to DFTD will also apply to DFT2 (The Veterinarian,January 2016). This second facial tumour disease is no longer confined to Tasmania’s southern peninsula, and it has serious implications for conservation management of devil populations in the wild, including the few DFTD-naïve populations that still exist in the state’s more remote regions.

“There’s much more research to do but the information we have at a local spatial scale is quite conclusive in respect of the disease becoming endemic. This has important consequences for management. The conservation dilemma we face now is weighing up the options of a perceived ‘do nothing’ approach, which tends to be unpopular both with the general public and with governments, or an intervention approach conducted in a restricted area that can be controlled and monitored until the model is proved to be beneficial,” he said.

While there is no imminent risk

of extinction, and devils appear to besolving the problem of adapting to the disease through natural selection, Hamede said it was crucial to keep monitoring and protecting affected devil populations long-term because it was these animals that possessed the key adaptive traits for future generations.

“We have thousands of devils throughout Tasmania so there’s no imminent risk of extinction. This doesn’t mean that in 2024 there may be other things that need to be considered because extinctions are rarely driven by one factor. They act in synergy with other threatening processes, so we also need to ensure all other threats are reduced, such as habitat loss and fragmentation, genetic deterioration in local populations, and roadkill,” he said.

“The tumour is in the detail: local phylogenetic, population and epidemiological dynamics of a transmissible cancer in Tasmanian devils’ is available at onlinelibrary.wiley.com/ onlinelibrary.wiley.com/doi/full/10.11 11/eva.13569

■ ANNE LAYTON-BENNETT

Weather and population density may increase spread of toxoplasmosis

From page 7 such as cougars and bobcats, freeranging domestic cats, and stray and feral cats. The data spanned regions around the world, and the researchers examined a variety of human- and climate-related factors that could potentially be associated with the parasite’s transmission.

Analysis showed a greater degree of oocyst shedding was observed in places with higher human population density. It also found higher mean daily temperature fluctuations were associated with more shedding specifically from domestic cats, and that higher temperatures in the driest quarter of the year were associated with lower shedding from wildcats.

“As one of the most common zoonotic parasites in the world, observing how Toxoplasma gondii oocyst shedding may change disease patterns in human and wildlife hosts could highlight pathways to reduce current and future pathogen transmission,” Zhu said.

In noting the findings did not prove any causal relationships, combined with the evidence from

TheVeterinarian

From page 1

Ord’s contributions are relevant for birds, mammals, fish and insects and his approach integrates detailed field studies with sophisticated comparative methods.

Some of his contributions listed in the nominator’s report include:

■ Being the first to discover that the intensity of aggressive interactions can drive the evolution of increasingly elaborate territorial signals across lizard species

■ Showing how the phenomena of plasticity and adaptation to environmental noise is virtually ubiquitous across all animal species and has repeatedly led to the independent evolution of animals using identical strategies to cope with environmental noise

Ord’s ‘curiosity-driven science’ has also translated well to broadcast media and his research has featured in several BBC Attenborough documentaries including Planet Earth II (2016), and Blue Planet II (2017).

■ ANNE LAYTON-BENNETT

Abstracts - equine behaviour

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previous studies, the study showed rising human population density and temperature fluctuations may create environmental conditions able to exacerbate the spread not only of toxoplasmosis but also other infectious diseases, and the focus for policymakers shouldbe managing feral cat populations to help reduce toxoplasmosis transmission.

“Changes from climate or human activities can affect disease transmission in ways we don’tfully understand yet. In our study we can see how these factors may be associated with changes in toxoplasma shedding by cats, which in turn can affect the risk of exposure to vulnerable people and wildlife,” Zhu said.

‘Morepeople, morecats, moreparasites: human populations density and temperature variation predict prevalence of Toxoplasma gondii oocyst shedding in free-ranging domestic and wild felids’ is available at doi.org/10.1371/ journal.pone.0286808

■ ANNNE LAYTON-BENNETT

Connection is key to mental wellbeing

From page 29 in young adulthood. Instead of processing her anxiety and depression, she threw herself into work and motherhood. It was only through later studying counselling that her supressed memories resurfaced. Another great loss forced her to get counselling herself and she began practising mindfulness. “I now know from my own personal experiences that it's okay to reach

out for help,” she says. “It's a bit like putting on the mask on yourself first in a plane. Weneed to look after ourselves first.”

Garryand Shirley continue to volunteer their time supporting others with mental ill health.

“We've got to get out there and reach these isolated rural and regional communities,” Shirley says. “That's what we're passionate about.”

From page 14 or poorly applied handling and training techniques. The potential contribution of each of these aspects must be considered when attempting to reduce or eliminate undesirable behaviours. Effectively modifying the existing behaviour includes investigation and treatment of potential physiological causes, assessing and adjusting existing handling, husbandryand management, and undertaking behaviour modifying training. Unlike in the treatment of dogs and cats, the use of psychotropic agents is uncommon in equine behaviour medicine but the benefits of using these agents in appropriate cases is gaining recognition. This review discusses potential causes for the development and maintenance of undesirable behaviours in horses and highlights the various considerations involved in determining the most appropriate course for reducing or eliminating these behaviours. There is also a brief discussion about the potential role of psychotropic agents as an additional component of an overall behaviour modification plan to reduce or eliminate undesirable behaviours in horses.

Sharon L Carroll1,Benjamin W Sykes2,Paul C Mills3 Vet J.2023 Jun-Jul;296-297:105985. doi: 10.1016/j.tvjl.2023.105985.

1School of Veterinar y Science, University of Queensland, Gatton, Queensland, Australia. Electronic address: s.carroll@uqconnect.edu.au.

2School of Veterinary Science, University of Queensland, Gatton, Queensland, Australia; School of Veterinary Science, Massey University, Palmerston North, New Zealand.

3School of Veterinar y Science, University of Queensland, Gatton, Queensland, Australia.

All material in The Veterinarian is subject to copyright and must not be reproduced wholly or in part without the written permission of the Editor. Views expressed in The Veterinarian are not necessarily those of The Veterinarian orSydney Magazine Publishers Pty Ltd.

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