The Modern Equine Vet July 2016

The Modern

Equine Vet www.modernequinevet.com

Vol 6 Issue 7 2016

The

Prepurchase exam:

Helping clients make informed decisions Tips for field anesthesia Steroids might reduce stem cell viability New Equioxx formulation

Table of Contents

The Business of Practice

The prepurchase exam:

4 Helping clients make informed decisions Cover photo: shutterstock/Olga_i

Surgery

Tips for field anesthesia....................................................................................................10 Infectious diseases

From Potomac horse fever to champion....................................................................16 dental

Tooth extraction causes bacteremia.............17 News

Steroids might reduce stem cell viability.....................................................3 FDA approves new Equioxx tablet........................9 Don’t let horses eat pistachios.........................13 Introducing Dr. Stephen Ostroff......................14 advertisers Merck Animal Health.................................................. 5 Boehringer Ingelheim................................................ 7

AAEVT............................................................................13

The Modern

Equine Vet Sales: Matthew Todd • ModernEquineVet@gmail.com Editor: Marie Rosenthal • mrosenthal@percybo.com Art Director: Jennifer Barlow • jbarlow@percybo.com contributing writerS: Paul Basillo • Kathleen Ogle COPY EDITOR: Patty Wall Published by PO Box 935 • Morrisville, PA 19067 Marie Rosenthal and Jennifer Barlow, Publishers percybo media  publishing

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News

A new study raises concern about the concurrent use of corticosteroids and stem cell therapy, suggesting that the drugs reduce the viability of the stem cells.

In this in vitro study, researchers looked at the effect that commonly used lameness drugs have on stem cells.

The researchers from the Royal Veterinary College, North Mymms, Hertfordshire, UK, took bone marrow derived stem cells in three horses and tendon derived somatic cells in two horses and resuspended them in media containing various commonly used drugs at clinically relevant concentrations. After drug exposure, they assessed the cell viability and proliferation.

At the start of the study, mean cell viability was 95%. Exposure to romifidine or mepivacaine did not significantly affect viability or proliferation. At the highest concentration of detomidine and butorphanol, stem cell viability was reduced significantly compared with controls. Although xylazine exposure caused a significant, dose-dependent reduction in stem cell viability compared with controls, overall population viability remained good. Mepivicaine, romifidine, butorphanol and detomidine had no effect on stem cell proliferation.

Both corticosteroid formulations tested (methylprednisolone and triamcinolone) significantly reduced viability at all doses. Methylprednisolone especially caused rapid stem cell death with no live cells observed after 1 hour in a high-dose suspension. Both corticosteroids caused a dose-dependent reduction in viability differentiated tendon derived cells.

Photo courtesy of The Royal Veterinary College

Steroids Might Reduce Stem Cell Viability

Delivering stem cells

Although these were in vitro results, the researchers said that they raise concern about the concurrent use of corticosteroids and stem cell therapy. In addition, the findings suggest that corticosteroid administration into the sheath of a damaged tendon cannot be recommended.

MeV

For more information: Edmonds RE, Garvican ER, Smith RKW, Dudhia J. Influence of commonly used pharmaceutical agents on equine bone marrow-derived mesenchymal stem cell viability. Equine Vet J. 2016 (Epub ahead of print June 24) http://onlinelibrary.wiley.com/doi/10.1111/evj.12590/abstract

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ModernEquineVet.com | Issue 7/2016

3

INternal Medicine

The

Prepurchase exam:

Helping clients make informed decisions

shutterstock/SSokolov

Jeff Berk, VMD, compares the prepurchase exami-

nation to taking a jigsaw puzzle out of the box, throwing the pieces on the table and putting the puzzle together to create a picture for the client.

“The physical examination, endoscopic examination of the upper airway and radiographic examination of the joints are some of the pieces of the puzzle that help to establish the level of risk regarding the purchase of any given horse,” explained Dr. Berk, of Equine Medical Associates in Lexington, KY. Buying a horse can be an emotionally and financially significant purchase for many buyers, according to Christopher “Kit” Miller, DVM, owner of Miller & Associates in Brewster, N.Y. The veterinarian’s prepurchase examination is critical in a client’s decision to purchase a horse and is extremely important in forming and maintaining a strong doctor-client relationship. But to provide the best picture, the veterinarian must not only the have clinical expertise, but understand the horse’s intended use and the client’s goals, he said.

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M S

Safety In Numbers Some dewormers claim just one dose of their product is the best way to deworm your horse, but that’s simply not true.

Demand Safety: You won’t find a laundry list of warnings and precautions on the PANACUR® (fenbendazole) POWERPAC label because fenbendazole has a unique mode of action that makes it safe for horses of all ages, sizes, and body conditions.

Demand Efficacy: PANACUR® POWERPAC is the only dewormer FDA approved to treat ALL STAGES of the encysted small strongyle.1 Other dewormers miss a critical stage, EL3, which can account for up to 75% of the encysted small strongyle burden. Plus, it’s the best choice for treating ascarids — which are not just a problem in young horses!

So when it comes to which dewormer to trust, don’t forget there’s safety in numbers.

Consult your veterinarian for assistance in the diagnosis, treatment, and control of parasitism.

Do not use in horses intended for human consumption. When using PANACUR® (fenbendazole) Paste 10% concomitantly with trichlorfon, refer to the manufacturers labels for use and cautions for trichlorfon.

1

PANACUR® (fenbendazole) POWERPAC Equine Dewormer product label.

The Science of Healthier Animals 2 Giralda Farms • Madison, NJ 07940 • merck-animal-health-usa.com • 800-521-5767 Copyright © 2016 Intervet Inc., d/b/a/ Merck Animal Health, a subsidiary of Merck & Co., Inc. All rights reserved. 3290 EQ-PC-FP AD

INternal Medicine

Your Time Is Valuable, Don't Underestimate It

The prepurchase examination is an important service without many hard costs. The single biggest cost to the veterinarian is the amount of time that the examination takes.

Many veterinarians tend to underestimate how much time is involved. Make sure you do not underestimate or undervalue it, said Christopher “Kit” Miller, DVM. Most of the equipment needed to do a comprehensive clinical examination is already on the truck. Imaging and lab work for complete blood counts, drug tests and Coggins tests, are routinely done.

The veterinarian needs to consider, not just the time it takes to perform the prepurchase examination, but also the time to acquire and interpret the images and other findings.

And all the client communication that follows. That is communication with the buyer, communication with the trainer and sometimes with colleagues when you need a second opinion on a finding.

“It is important to clearly understand your client’s goals and expectations, so you can tailor your examination accordingly,” Dr. Miller said.

Provide enough information to make the client comfortable with his or her decision. “You have to satisfy yourself that they are hearing you and understand what you are saying,” Dr. Berk said, but don’t make the decision for them.

Don’t just list the examination findings either, said Dr. Miller, because the buyer wants to know the veterinarian’s opinion about the horse’s physical ability to perform in a specific discipline.

Multiple individuals, including the veterinarian, an agent, and a rider may be involved in an advisory capacity to the prospective buyer, explained Dr. Miller, and all of these personalities and opinions will want a say. Although the goal of the examination is to provide enough information for the buyer to make an informed decision about 6

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the horse's ability to perform, the results are used frequently to negotiate the value of the horse and ultimately it’s price, he said. Remember that the veterinarian works for and is accountable to the buyer, he recommended.

“The job of pairing the veterinarian's conclusions with the conclusions of the horse’s ability, the compatibility with the rider and particularly the prepurchase price, should be the job of the trainer and is not the job of the veterinarian,” Dr. Miller said. “I make it a point not to become involved in conversations regarding any of these three topics.”

Common ground

All examinations, regardless of the venue, consist of a visual and physical examination that includes watching the animal move, as well as some diagnostic testing, especially radiographs and sometimes flexion tests. Some veterinarians will also want to evaluate the airway with endoscopy.

A medical history is important, but not always readily available or complete, they said. “Those of us who do prepurchase examinations at competition venues know they are intermittently [available],” Dr. Miller said. “The medical history is a source of uncertainty for many of us because it is not clear what our legal obligation is as far as acquiring and verifying medical histories.”

At the very least, the physical examination should consist of an assessment of the horse’s eyes, heart, external genitalia and overall body condition, Dr. Berk said. Look at the conformation of the horse, the pedigree and the farm of origin. There should be a visual and manual examination of all four limbs.

Dr. Miller suggested seeing the horse in different situations if possible. He’s seen a few cases where the horse in the stall acted differently

than outside or where it took several individuals to hold the horse and “throw” the rider on it. That might not be a suitable horse for someone’s young daughter.

Besides a complete and thorough physical examination that emphasizes the skeletal muscles, carefully palpate the neck, back and distal limbs looking for wear and tear or previous injury.

Prior surgery?

“Part of the routine examination process will be watching the horse in motion to detect any subtle lameness or neurologic deficits. This part of the examination will vary depending on the age of the horse.

At a weanling or yearling sale, it would be customary to watch the horse walk and turn. At a sale of 2 year olds in training or older horses in training, in addition to watching them walk, it is also possible to observe the horse at the trot at the end of a shank,” Dr. Berk said.

“We will routinely check the belly for an abdominal scar or umbilical hernia,” he said. Most scars are not deal breakers, but it’s better for the veterinarian to find them, than the client after purchasing the horse.

In this particular puzzle the radiographic findings occupy a fairly large piece, according to Dr. Berk, who added, “But I think we need to talk about and carefully look at some of these other pieces because they all fit together to make the whole.”

There is no question that radiographic findings would be a deal breaker sometimes, but other times, they might not be. “There are many times where we have radiographic findings that are just findings and they need to be approached that way, as just another piece of the puzzle,” Dr. Berk said.

Which views to take

Imaging should be based upon the

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ModernEquineVet.com | Issue 7/2016

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INternal Medicine

If a vetted horse wins a lot of blue ribbons or is sold for a profit, a client will likely be satisfied with the exam. If it doesn't meet owner's expectations, the prepurchase exam will likely come under scrutiny. examination findings and be appropriate for the intended discipline, according to Dr. Miller. Make sure the client knows what images will be taken and why. “In our practice for our simple, uncomplicated prepurchase examination, our routine is to take digital radiographs of the front feet, front and hind fetlocks, hocks and stifles. We routinely take other images of the horse, but they are based upon our clinical examination findings or a specific client request.”

Ask: Which findings are likely to be performance limiting and which are likely to be well tolerated? “Keep in mind that when we are doing these prepurchase examinations on athletes and these show horses, a lot of them are on the older horse, a lot of them are competing and many are actually already performing at or above the level that are clients intend it to perform at. If you already have information about the horse’s physical ability to perform in the discipline, then for me, when you do the prepurchase examination, your clinical findings really outweigh the imaging findings,” Dr. Miller said.

The converse is true in the resale, investment horses, which tend to be younger. With no performance history, veterinarians are often more conservative in interpreting information. If there is any uncertainty, consult with a colleague or two, they suggested.

“There are differences of opinion about the value of survey endoscopy or survey ultrasound. It is not 8

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my habit to perform them in the absence of a clinical examination finding that would indicate them. Once again, it is important to make sure that your client knows that these are available so that you do them if your client desires,” Dr. Miller said.

Be consistent

He suggested developing a consistent, thorough routine. “I think if you develop your own routine then you diminish any likelihood that you would miss anything if you should happen to get interrupted in the middle of the examination or something. I perform the exact same prepurchase examination regardless of the horse’s intended use,” he said.

"The pedigree is important, Dr. Berk said, because it is the best measure of those intangible qualities that make a good race horse such as the inherent speed and endurance, the desire to win and the ability to withstand discomfort."

He said the pedigree might even help the veterinarian interpret radiographic findings. Some horses with incredible pedigrees will sell quite well even with some substantial radiographic findings.

Also look at the timed workouts if it is a 2-year-old training sale.

“These horses are typically working for either one-eighth or onequarter of a mile, and it’s timed and you want to know first of all how fast that horse is, what the time was, whether the horse did that time under duress or whether it was done

easily,” Dr. Berk said.

At the end of the examination, there should be a list of critical findings, as well as an assessment of their significance to the current and future health of the animal.

No horse is perfect

“However, the mere presence of findings does not necessarily disqualify a horse from consideration by a particular client. Many veterinarians will discover findings that they may consider significant and automatically fail the horse, removing it from consideration for purchase. This is essentially deleting an important step in communication process as if the client has no risk tolerance whatsoever,” Dr. Berk said.

“If there’s one thing worse than a client buying a horse with a veterinary finding and having that finding end up negatively affecting the horse, it’s when a client with a highrisk tolerance deliberately passes on one good horse after another only to watch those horses compete at high levels for other owners,” he said.

If the examination was thorough, it is very common to encounter abnormal findings in clinically normal horses, they said.

“If you vet a horse and it wins a lot of blue ribbons or is sold for a profit, your client will likely be satisfied with your examination,” Dr. Miller said.

“However, in the event a horse or pony does not meet the owner's expectations, there is a possibility that your prepurchase examination is going to come under some scrutiny.”

Not a good fit

Not all client-veterinarian relationships work, so you can say no. “I guess my point here is that we’re all familiar with the concept of being hired and fired by clients, but you have the same privilege. You can decide when someone asks you to do their work, whether you think it’s a good fit or not, and I would suggest to you that if you’re feeling uncomfortable, like you don’t have good communication going, you have the opportunity if you choose to do so to not work for that person and sometimes it can be a very good decision, particularly with regard to

liability,” Dr. Berk said.

The veterinarian should always disclose to a potential buyer that he or she has been responsible for the care of the horse in question and offer the client the option to use another veterinarian. Often, the buyer will be comfortable with their veterinarian doing the examination in spite of the pre-existing relationship with the seller. There’s a perceived advantage because the veterinarian knows the horse to some degree by virtue of having been its caretaker.

But it could cause an ethical dilemma if the horse has an issue.

“You now possess information that

has been obtained on behalf of the seller. That information has been paid for by the seller and technically is owned by the seller. Now working for the buyer, you have information that may affect the suitability of the horse for that particular buyer, and yet, you’re legally unable to transmit that information to them. In a situation like this, it would be prudent for you to ask the buyer to use another veterinarian,” Dr. Berk warned.

The two veterinarians spoke at the 61st Annual Convention & Trade Show of the American Association of Equine Practitioners in Las Vegas.

MeV

FDA Approves New Formulation of Equioxx let formulation to market for horses. Having all three Equioxx formulations allows for consistent therapy with the same active ingredient.”

He noted that when it comes to giving medications to performance horses, owners, trainers and veterinarians should read the rules specific to each association or show, ensuring they are in compliance.

Equioxx Tablets will be available by prescription only. As with any prescription medication, prior to use, a veterinarian should perform a physical examination and review the horse’s medical history. A veterinarian should advise horse owners to observe for signs of potential drug toxicity. As a class, NSAIDs may be associated with gastrointestinal, hepatic and renal toxicity.

Use with other NSAIDs, corticosteroids or nephrotoxic medication should be avoided. Equioxx has not been tested in horses younger than 1 year of age or in breeding horses, or pregnant or lactating mares. For additional information, refer to the prescribing information or visit equioxx.com.

MeV For more information, go to www.merial.com; @Merial.

shutterstock/Abramova Kseniya

The FDA recently granted a new formulation of firocoxib (Equioxx, Merial) for use in a tablet form, which will be available to veterinarians in early fall.

For almost 10 years, firocoxib has been the only coxib non-steroidal anti-inflammatory drug (NSAID) approved for use in horses as a once-daily treatment to control joint pain and inflammation associated with equine osteoarthritis.

Firocoxib is the only NSAID approved for use up to 14 days by both the AQHA and USEF and now gives the choice of three formulations, depending on the specific need of the horse. Injection is best to initiate therapy, while the paste is a convenient form for accurate dosing, especially for small horses and performance horses. And now, the tablets are easy to administer, with or without feed.

“Veterinarians and horse owners have been waiting for a tablet option of Equioxx from Merial,” said Hoyt Cheramie, DVM, MS, manager, Merial Large Animal Veterinary Services. “The FDA approval process is very stringent, and we are proud to bring this new tab-

ModernEquineVet.com | Issue 1/2016

9

surgery

Tips for

Photo by bob@boblangrish.co.uk

Field Anesthesia Equine veterinarians do not usually have the luxury of a surgical suite to manage procedures and must know the best ways to provide sedation, anesthetic and pain relief to get the job done in the field. Keith R. Branson, DVM, MS, DACVAA, a large animal anB 10

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esthesiologist at the University of Missouri, offered these tips for managing an animal during a field surgery, such as a castration.

For many of these procedures, the veterinarian wants something that will keep the horse sedated for long enough to do the procedure,

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but not so long that it gets into trouble during recovery. Xylazine, an analogue of clonidine and an Îą-2 agonist, and ketamine, a nonbarbituate anesthetic, are a classic combination for field procedures.

The horse typically receives IV xylazine and after five minutes or so,

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Supportive Care Supportive care for procedures that use injectable anesthesia are minimal.

For short procedures, the veterinarian can make the call whether or not to intubate the horse, according to Keith R. Branson, DVM, MS, DACVAA, a large animal anesthesiologist at the University of Missouri.

“Horses are one species that I don’t get too worried about intubating when they’re anesthetized because they protect their own airway well, they don’t regurgitate, they have a large open airway, so it’s not always indicated to intubate the horse. If you want to intubate them they’re one of the easier species to intubate.

“We just place some sort of an oral speculum, we just use a piece of PVC pipe that’s big enough for the endotracheal tube to fit down, pass the endotracheal tube blindly, you put the tip of the bevel ventrally and it seems to work best. And it either is going to meet resistance and you know you’re not going in the trachea, back up again and try again.”

He said to make sure the head is well extended and get the tube down quickly. “I’m not sure why but if you move the tube real slowly, they’re much more likely to spasm down.”

Although with most injectable anesthesia, it is unnecessary to put a horse on fluids or monitor blood pressure, Dr. Branson said he would consider supplemental oxygen. He uses a human resuscitation kit that has a small oxygen tank in it with the demand valve attached to it, so you can either hook this up and as the horse breathes they’ll get some supplemental oxygen, or if you should need to ventilate an animal, there’s a button on the back of the demand valve that you can push that will deliver a breath.

With an E-tank, you can ventilate a 1,000-lb. horse for 20 to 30 minutes and if they’re just using it as a source of supplemental oxygen while they breathe spontaneously, you can probably get an hour out of it.

when it is good and sedated, add the IV ketamine.

It is the most “basic general anesthetic protocol” for equine veterinarians in the field, and it works pretty well, but it is not perfect, Dr. Branson said. “There’s not a lot of analgesia in that combination, we don’t have really good muscle relaxation. If you just use xylazine and ketamine alone, we don’t have a real relaxed horse.”

Many add butorphanol, which is an opioid, to increase sedation, but it doesn’t help with muscle relaxation,

he said. “Certainly if I have a horse that doesn’t respond really well to xylazine, meaning they’re not real sedate from their initial dose of xylazine, butorphanol is what I will usually add to the xylazine rather than more α-2,” because it will enhance the sedation of xylazine.

To get better muscle relaxation, one can add a benzodiazepine— either diazepam or midazolam— to the general anesthetic protocol.

“Typically it’s given either with or immediately prior to the IV ketamine,” he said.

Although use together is not contraindicated, most veterinarians would not use an opioid and a benzodiazepine together. Dr. Branson said he often chooses butorphanol because the opioid relaxes the horse enough for most procedures.

Another option is to apply local anesthetic if appropriate. So, for a castration, he might provide an intra-testicular injection of lidocaine, which helps decrease the response when one puts the emasculators on the cord. Wait a bit to give the lidocaine a chance to decrease sensation, he suggested.

The xylazine and ketamine provide about 10 minutes of good anesthesia; if longer sedation is needed, then consider using another anesthetic. Dr. Branson usually chooses Telazol (Zoetis), which is a combination of zolazepam and tiletamine, as the induction drug.

“You get a little longer time with this, although again the periods do overlap a little bit,” he said.

However, Telazol is costly, he said.

“A 1,000-lb. horse is going to take a lot more Telazol and you’re looking at several times the price of xylazine and ketamine, plus butorphanol or benzodiazepine. So you add a lot of cost to the protocol and you get a small amount of extra time.”

Another option is to redose the xylazine and ketamine with about half the initial dose. If a longer acting α-2, such as detomidine, is part of the induction, one would probably only need to redose the ketamine, he said.

“If you redose much more than once, the quality of recovery really starts to deteriorate,” he said, so if even longer times are needed, he typically uses a different protocol, possibly a combination of guaifenModernEquineVet.com | Issue 7/2016

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surgery

esin, ketamine and an α-2 agonist.

The original recipe for this, which was called triple drug, was 1 L of 5% guaifenesin, 10 mL of ketamine and 5 mL of xylazine, he said.

“Typically we induce them with xylazine and ketamine like we would a normal field castration, and then give 100 to 200 mL of triple drip pretty rapidly after induction just to make sure they’re good and asleep. And then you maintain them at 2 mL/kg/hour,” he said.

“Now this is one of the times I don’t go metric because 1 mL per 1 lb per 1 hour is real easy to remember. That means a liter bag of triple drug basically gives you an hour of anesthesia for a 1,000 pound horse.

“So if you’re trying to figure out how much you need, that’s a pretty easy way to remember it and then if you figure out, you know, a drip rate for 1 mL per pound per hour for a 1,000 horse, if you have a 500 pound horse it’s about half that rate, if you have a 750, it’s about two-thirds that rate, and that’s a pretty predictable rate.

“This is nice for IV anesthesia because we don’t see a lot of variation in the dose. If you put a normal healthy horse at a milliliter per pound per hour, it’s almost a sure bet it’s going to stay asleep

and it’s not going to be too deep at the end,” he said.

He uses caution in older horses, especially if they have poor renal function, because the guaifenesin tends to accumulate longer in older horses, which can affect muscle tone and cause problems when the animal awakens and tries to stand.

Adding additional ketamine (20 mLs in a 1 L bag) can mean using less guaifenesin, which could improve this adverse effect, he said.

When using IV or injectable anesthesia, keep the horse fairly light if possible, he said, but keep an eye on respiratory rate and character to make sure they aren’t too light and come up too soon.

“Often if I’m not looking at the horse but I hear something different about the way they breathe, the respiratory rate increases, they take a big deep breath and hold it for a moment and let out, that’s a real key indicator that maybe the horse is getting a little bit light. So I really watch respiratory rate and character. And it’s nice because if you’re doing the surgery you can listen for stuff like that or you can watch the abdomen while they breathe while you’re doing the castration, so it’s something you can do while you’re doing the surgery

that’s going to give you a clue that something may be wrong,” he said.

Propofol can be useful, particularly in foals, when one just needs a short sedation because they can be brought back up quickly. It’s expensive, but not as pricey as it used to be.

Positioning is important, pull the front leg forward and remove the halter to prevent any nerve damage if possible. “When they’re down longer, especially getting that down front limb out from under them so you don’t get paralysis, and keeping them light so that they’re not laying there forever,” he suggested.

Waking up and standing is a critical point, especially during a lameness procedure, he said, and there are times when you might want a longer recovery time. “If you’re knocking them down to do a cast change, for instance, one of the things you have to consider is you don’t want them to get up 5 minutes after you put the cast on; you want the cast to cure well. So, in those cases I’ll either extend the anesthesia out for 10 or 15 minutes after we’re done or make sure they’re fairly deep when we’re done so that they’re not going to hop right up and break a cast before it’s had a chance to cure,” he said . MeV

Donkeys, Ponies and Mules Donkeys, ponies and mules don’t always go down well with triple drip. Since thiopental is not available in the United States anymore, an alternative is needed. “I’ve done a couple little donkeys and a zebra with propofol and it worked really well. But in general, what I do for donkeys, ponies and mules is I premed them with an α-2 IV just like a normal induction. If they’re a little worked up I’ll give them some butorphanol and then I run 5% guaifenesin with nothing added to it, no ketamine, no xylazine, not triple drug, just straight 5% guaifenesin, till there’s an obvious effect."

Once he sees a “pretty pronounced relaxation” he gives them an IV bolus dose of ketamine and if needed, he continues the guaifenesin after they’re down.

“Now donkeys metabolize ketamine better than other species, and ponies and mules appear to be just pharmacodynamically less sensitive to ketamine, so this allows us to have the guaifenesin there, which has muscle relaxant effects, has sedative effects, and we can basically give that to effect as part of the induction protocol until the thing is down.

“And then you can either switch to triple drip for maintenance or give an additional bolus of ketamine if you’re just doing a field castration.

And to be honest with you, I’ve used this more for induction prior to gas but I certainly have done some castrations with this. Typically we switch them over to triple drug for the castrations.”

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news notes

As autumn approaches, remind owners to keep their horses out of pistachio orchards, because the leaves and seeds of the genus Pistacia can cause hemolytic anemia, and be fatal, if ingested.

In the fall of 2013, following the acute deaths of five mares from a large herd, two surviving mares were brought to the University of California at Davis veterinary hospital after two days of lethargy and icterus. The deceased horses had varying degrees of colic, ataxia, pigmenturia, pale and icteric mucous membranes, lethargy and inappetance. All died within 48 hours of initial signs.

While UC Davis’ Equine Medicine Service worked to save the two mares, one of the veterinarians on the case, resident Rana Bozorgmanesh, BVSc, started researching the cause of the deaths. She and the service team, along with members of the toxicology department, discovered that the sick horses had access to a planted Pistacia orchard (containing the species P. atlantica, P. terebinthus, and P. chinensis) following the fall harvest. (The most common species of the Pistacia genus is P. vera, or the pistachio nut.) There were no recent changes in herd management or housing, except for the felling of the Pistacia orchard shortly before the first horse developed clinical signs; the owner had witnessed the horses eating from trees that had been cut down. Other horses on the property that were not allowed access to the orchard did not exhibit any signs of illness.

A site visit by Dr. Bozorgmanesh, along with veterinary students and staff, was performed to inspect the property for possible toxin exposure. They sampled the water, hay, trees and vegetation to investigate potential intoxication as the cause of hemolytic anemia, usually associated with an oxidant toxin such as maple trees, onions, or other plants associated with oxidant damage or hemolysis in horses. None of these were found on the property.

The owner was instructed to move the herd away from the Pistacia trees and to administer activated charcoal to horses observed to ingest Pistacia leaves or seeds. Upon moving the mares to a smaller area of the property with no access to Pistacia trees, there were no additional illnesses or deaths.

Courtesy of University of California at Davis

Don’t let horses eat pistachios

Pistacia trees are not native to North America, but are found in California, as well as several other states in the Southwest and Southeast, where fertile land produces much of the world’s marketable Pistacia products. The California outbreak arose in the fall, the same seasonality as reported with red maple leaf toxicosis, when the leaves are wilted and falling off the trees. A similar incident with Pistacia occurred in Arizona, also at a time when leaves were falling off the tree.

“While the horses had access to the trees throughout the remainder of the year, we propose the problem lies with the felled and wilted leaves,” said Dr. Bozorgmanesh, who ultimately became the lead author on this groundbreaking clinical research. “The felled trees in the California outbreak would have allowed for easy access and ingestion of large quantities of wilting leaves and seeds by the horses, thus accentuating these effects.”

In vitro studies by UC Davis toxicologists showed extracts of the seeds and leaves induced lysis of horse red blood cells in the laboratory. Further research is required to identify the exact pathophysiology of Pistacia tree toxicosis, the toxic principles involved and the quantities required to cause clinical disease in horses.

“Until that time, it is clear that horses must be isolated from these trees to prevent acute hemolytic anemia and death,” added Dr. Bozorgmanesh. MeV

Pistacia trees are found in California and states in the Southwest to the Southeast.

For more information: Bozorgmanesh R, Magdesian KG, Rhodes DM, et al. Hemolytic anemia in horses associated with ingestion of Pistacia leaves oxidant-induced damage to equine erythrocytes from exposure to Pistacia atlantica, Pistacia terebinthus, and Pistacia chinensis. J Vet Inten Med. 2015;29(1):410-13. http://onlinelibrary.wiley.com/doi/10.1111/jvim.12532/abstract ModernEquineVet.com | Issue 7/2016

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news notes

Introducing the FVM's Dr. Stephen Ostroff

Photo courtesy of the FDA

Stephen Ostroff, MD, is the FDA’s new Deputy Commissioner for Foods and Veterinary Medicine (FVM). He succeeds Michael R. Taylor, who became the first deputy commissioner for the FVM program in 2010. Dr. Ostroff served as acting FDA commissioner from April 2015 until Congress confirmed Dr. Robert Califf’s appointment in late February 2016.

Dr. Ostroff’s career has been dedicated to public health. Prior to his tenure as acting commissioner, he was named the agency’s chief scientist in 2014, responsible for leading and coordinating FDA’s crosscutting scientific and public health efforts. He joined FDA in 2013 as chief medical officer in the Center for Food Safety and Applied Nutrition and senior public health advisor to Mr. Taylor.

Before coming to FDA, Dr. Ostroff served as deputy director of the National Center for Infectious Diseases at the Centers for Disease Control and Prevention (CDC), and as Director of the Bureau of Epidemiology and Acting Physician General at the Pennsylvania Department of Health.

Q: What are your goals for the FVM program?

The primary goal is embodied in our public health mission: to ensure that Americans have access to the safest and most healthful food supply possible. To accomplish that, we must have a robust program to promote the safety of the food supply through full implementation of the FDA Food Safety Modernization Act (FSMA).

Accomplishing this goal also means that we base our decisions on the best available scientific information.

Q: How do you get the best science?

You have to cast a wide net. Sometimes that means relying on scientific work that we do ourselves at FDA. But more often than not, it’s relying on studies done outside the agency. That’s why it’s so important for us to have a strong science base, with scientists who can work collaboratively with others who are conducting research that we can use to make our regulatory decisions and who can evaluate such science.

There’s a lot of good and valuable work that’s done in many different sectors. We need to be able to look at all of the available data and analyses to make good decisions, regardless of source.

Q: W hat about veterinary medicine? What is the priority there?

Antimicrobial resistance is a very important topic for human and veterinary medicine. On the veterinary medicine side, it is important that we continue to address the role and contribution of antibiotic use in food producing animals to antimicrobial resistance. We have initiated a number of steps to reduce and ultimately eliminate non-judicious uses of medically important antimicrobial medications to enhance growth or feed efficiency in food animal production. This includes working collaboratively with stakeholders to secure 14

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voluntary removal of production indications from the labels of medically important antibiotics and bringing use of antibiotics in food animals under the supervision of a veterinarian. It will be very important to make sure we can monitor the impact of these steps to see if they are having the intended effect and to determine whether additional steps may be appropriate.

In addition to our work with the National Antimicrobial Resistance Monitoring System (NARMS), we are collecting data on the sales of antimicrobial medications. We recently expanded sales data collection to require that sponsors of antimicrobial medications provide estimates of their sales data broken down by species of food-producing animals, in addition to overall sales. We need to work with the U.S. Department of Agriculture and the food animal industry to gather information on actual use patterns on the farm and to make sure that any use is under veterinary oversight for specific animal health purposes.

Q: How important will public engagement be going forward?

We are much more effective as an agency when we work with broad coalitions of partners and when we communicate what it is we’re doing and why we’re doing it.

Transparency, communication and open dialogue are very important.

Having now been in OFVM for a few months since stepping down as acting commissioner, I’ve marveled at the range of strategic partnerships and coalitions that have been developed in FVM over a period of years. I give a lot of that credit to Mike Taylor, who had an extraordinary ability to bring together a variety of stakeholders who often don’t often share the same viewpoints to look for areas where MeV consensus can be built.

AAEV T M E M b E r s h i p Membership in the AAEVT is open to all veterinary technicians, assistants, support staff and those employed in the veterinary health care industry worldwide. Student membership is open to those currently enrolled in an AVMA/CVMA accredited veterinary technology program.

AAEVT Membership • • • • • • • • • • •

Bi-Annual Newsletter Weekly “HoofBeats” Email Newsblast Full access to www.aaevt.org, including the Career Center and the Library Up-to-date information on the AAEVT Discounted registration for AAEVT Regional Meetings and the annual AAEP/AAEVT Convention NTRA, Working Advantage and Platinum Performance Benefits The opportunity to participate in the AAEVT Online Certification Program or to become a member of the AEVNT Academy-Specialty in Equine Veterinary Nursing Scholarship opportunities.

AAEVT’s Equine Manual for Veterinary Technicians (Blackwell Publishing 20% discount on purchase price) Opportunity to attend Purina’s Annual Equine Veterinary Technician Conference - All Expenses paid!

AAEVT Objectives • • • •

Provide opportunities for CE, training, communication, and networking Educate the equine veterinary community and the public about our profession Inform Members of issues affecting our profession Assist in providing the best medical care to improve the health and welfare of the horse

AAEVT Online Equine Certification Program

• A three course, 10 module, equine-only online program offered through ACT • Geared toward Credentialed Veterinary Technicians, Assistants, Support staff, & Students • Areas of study include: equine medical terminology, anatomy and physiology, parasitology, laboratory, diagnostics, equine basics (breeds, wellness, husbandry,) diagnostic procedures, emergency medicine, restraint, pharmacology, surgical assistance and anesthesia, equine office procedures • A certificate of completion is awarded to those who: Successfully complete required courses Complete the list of required skills (per a supervising DVM who is an AAEP member) Attend an AAEVT regional CE symposium and participate in the we labs • Those individuals who successfully complete the programs will be recognized as AAEVT Certified Equine Veterinary Technicians / AAEVT Certified Equine Veterinary Assistants depending on their current designation. The certificate is recognized by the AAEVT and the AAEP but does not grant the credentialed status by the AVMA • For more information go to www.aaevt.4act.com or call 800-357-3182

AAEVT Mission Statement: To promote the health and welfare of the horse through the education and professional enrichment of the equine veterinary technician and assistant.

Fo r m o re i n f o r m a t ion v ist w w w.a ae vt.or g

ModernEquineVet.com | Issue 7/2016

*American Association of Equine Veterinary Technicians and Assistants

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infectious disease From Potomac Horse Fever to Champion: A Ladies' Club Winner

Photo courtesy of the New Bolton Center

By Louisa Shepard Squeezing through a tiny gap between horses in the stretch, Tutti came in first over the wire in the $200,000 Grade II Santa Ana Stakes in Santa Anita. The March race was the 6-year-old mare’s first graded stakes win after stringing together a nice fall and winter campaign that included victories in the $75,000 Churchill Distaff Turf Mile Stakes and $100,000 South Beach Stakes.

A striking dark grey Thoroughbred imported from Italy, Tuttipaesi is owned by Valor Ladies LLC, a partnership of women who invest in racehorses. Tutti, as she is affectionately called, is the first of the Ladies’ four fillies.

The impressive win was a surprise: Tutti had come back after 18 months of rest to recover from a lifethreatening illness that landed her in the isolation wing at Penn Vet’s New Bolton Center in Kenneth Square, Pa. The top filly in Italy in 2012, she was imported as the first Valor Ladies’ racehorse. After coming in second in a Grade I race at Keeneland, Tutti suffered a hairline condylar fracture of her left foreleg in May 2013. Following treatment at New Bolton, she went to Grattan Farm in Oxford, Pa., to recover.

While at the farm, Tutti came down with an illness. Her primary veterinarians thought it could be colic, and she was sent back to New Bolton. Since she had a fever upon arrival, Tutti was placed in the isolation wing of its Moran Critical Care Center.

“It turned out that she had Potomac Horse Fever, which is a pretty common disease in this area. It is sometimes fatal if not caught and treated appropriately,” said Rose Nolen-Walston, DVM, DLAIM, associate professor of Internal Medicine. “It’s a scary disease. As soon as we suspect it, we treat it, even before the test results come back.”

Tutti: A case of Potomac Fever almost ended her career.

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Symptoms are high fever, diarrhea and often laminitis, which can be severe and hit early in the course of the disease. Potomac Horse Fever is caused by a bacterium that undergoes a life cycle that involves freshwater snails, a worm that infects the snails, and one of several forms of flying insects. Horses are infected by accidentally eating tiny mayflies or caddis flies that settle on their hay and feed.

Treatment includes IV antibiotics (oxytetracycline) and low-dose anti-inflammatories. In addition, IV fluids help replace electrolytes, and ice boots reduce the chance of laminitis.

Even after symptoms had resolved, Tutti’s blood protein levels were still dangerously low, Dr. NolenWalston said. Ultrasonography revealed right dorsal colitis, the thickening and inflammation of a section of intestine. Dr. Nolen-Walston concluded that Tutti had a reaction to the nonsteroidal anti-inflammatory drugs. “Even though she hadn’t had high doses of NSAIDS, she was affected,” she said.

In some horses, the colon never heals completely, causing persistent protein losses through the damaged intestine or scar tissue causes a narrowing of the intestine that can predispose the horse to colic, Dr. Nolen-Walston said.

Tutti responded well to treatment, and after five days was cleared for discharge on a low-bulk diet; supplemental corn oil and psyllium, which provide nutrients for intestinal cells; and misoprostol, a medication that improves blood flow to intestines.

Dr. Nolen-Walston said she should never be given NSAIDs. “The biggest question was whether she would bounce back from disease to be a successful race horse, and could she be successful as a racehorse drug-free?”

Tutti went back into training under Bill Mott in the fall of 2014, while spending some time with Bruce Jackson at Fair Hill in the summer of 2015.

“She was really rusty. It took awhile to get her back to where she was before,” said Megan Jones, founder of Valor Ladies, and Vice President of Team Valor International of Lexington. “Bill and Bruce did a fantastic job with her and gave her all the time that she needed. We were very careful with her diet early on, and she still doesn’t receive any NSAIDS.” The plan for Tutti is to continue racing this year, and then breed her to Animal Kingdom next year, Ms. Jones said.

MeV Edited from a story on the Penn Vet website at http://www.vet.upenn.edu/.

dentistry

Tooth Extraction Causes Bacteremia Bacteremia occurs in almost all horses during tooth extraction, most commonly at the time of gingival incision. Although some horses do develop fever, none of the horses in one study that looked at this relationship suffered any serious complications as a result of the bacteremia. However, this could increase the risk of a complication, the researchers said..

In this prospective study, the prevalence of bacteremia in horses following tooth extraction and bacterial species involved was documented in 20

Photo courtesy of Equine Veterinary Journal.

Blood and swabs from extracted teeth were cultured under aerobic, anaerobic and microphilic conditions. Horses’ temperatures were recorded every three hours until 48 hours postsurgery.

After surgery, the temperature of three horses rose to 38.0-38.5° C while four horses developed pyrexia (>38.5° C). The mean time for the first temperature elevation to occur was around eight hours post-operatively. Bacteremia (indicated by positive blood culture) was detected in 18 out of 20 (90%) of horses at one or more times. In most of these (12 horses), mixed growth of aerobic and anaerobic bacteria were present.

Bacteremia was detected in some horses at almost all measured times, generally within the first 50 minutes of surgery.

The highest number of positive cultures was obtained one minute after the start of surgery, and elevation of the gingiva was the part of the procedure most commonly associated with bacteremia suggesting that bacteria can enter the bloodstream via damaged capillaries in gingival tissue without any manipulation of the tooth.

From blood, Streptococcus and Actinomyces were the most Equine dental radiograph. New evidence points to bacteremia from dental procedures, and some common aerobic isolates and fever, but know one knows if this will be significant to the horse's health. There is the potential for Fusobacterium was the most complications. common anaerobic isolate. horses presented with dental disease to a single In all but one horse, both aerobic and anaerobic facility in Germany. isolates were obtained from extracted teeth and Half underwent cheek tooth extraction and the a large range of bacterial species were found. No other half underwent canine or incisor extraction. particular bacteria were associated with specific Standard oral extraction under sedation and lodental diseases. cal anesthesia was performed. Blood samples for Furthermore, the bacterial flora did not seem culture were obtained immediately after catheter to correspond with the gingival health of the paplacement and at 1, 5 and 20 minutes after the tients. These results highlight that there is potenfirst gingival incision and then every 30 minutes tial for complications associated with bacteremia thereafter until the tooth was extracted. At each e.g. infectious endocarditis and pneumonia in sampling point the surgical activity was recorded. tooth extraction cases.

MeV

For more information: Kern I, Bartmann CP, Verspohl J, et al. Bacteremia before, during and after tooth extraction in horses in the absence of antimicrobial administration. Equine Vet J. 2016 (Epub ahead of print June 4) http://onlinelibrary.wiley.com/doi/10.1111/evj.12581/abstract ModernEquineVet.com | Issue 7/2016

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