The Modern Equine Vet August 2015

The Modern

Equine Vet www.modernequinevet.com

Vol 5 Issue 8 2015

Role for MRI in diagnosing some foot pain Upper airway surgery Omega-3 fatty acids Things are looking up for the equine industry Yes, that horse is laughing at you!

Table of Contents

Cover story:

Role for MRI in 4 diagnosing some foot pain Cover:Shutterstock/Theunis Jacobus Botha

nutrition

Horses can absorb omega-3 fatty acids............................................................................8 Respiratory

Advances in upper airway surgery...................................................................................11 Behavior

I can see it in your face.........................................................................................................14 Business of Practice

Things are looking up for the equine industry............................................................16 News

Buprenorphine or butorphanol for peri-operative use?..........3 Treatment of metabolic syndrome...................................................7 Riding a horse more complex than simulator.......................13 Diagnosing Lyme disease in horses is difficult ...................18 Keep up your guard for WNV.....................................................19 ASPCA grants $200,000 for racehorse rescue.......................19 advertisers Shanks Veterinary Equipment.................................. 3 Lifeline Proformance Supplements......................... 5

Avalon............................................................................. 7 Luitpold Animal Health.............................................. 9

The Modern

Equine Vet Sales: Robin Geller • newbucks99@yahoo.com Editor: Marie Rosenthal • mrosenthal@percybo.com Art Director: Jennifer Barlow • jbarlow@percybo.com contributing writerS: Paul Basillo • Kathleen Ogle Louisa Shepard COPY EDITOR: Patty Wall Published by PO Box 935 • Morrisville, PA 19067 Marie Rosenthal and Jennifer Barlow, Publishers percybo media  publishing

2

Issue 8/2015 | ModernEquineVet.com

LEGAL DISCLAIMER: The content in this digital issue is for general informational purposes only. PercyBo Publishing Media LLC makes no representations or warranties of any kind about the completeness, accuracy, timeliness, reliability or suitability of any of the information, including content or advertisements, contained in any of its digital content and expressly disclaims liability of any errors or omissions that may be presented within its content. PercyBo Publishing Media LLC reserves the right to alter or correct any content without any obligations. Furthermore, PercyBo disclaims any and all liability for any direct, indirect, or other damages arising from the use or misuse of the information presented in its digital content. The views expressed in its digital content are those of sources and authors and do not necessarily reflect the opinion or policy of PercyBo. The content is for veterinary professionals. ALL RIGHTS RESERVED. Reproduction in whole or in part without permission is prohibited.

news notes

Buprenorphine or butorphanol for peri-operative use?

When given as part of premedication, buprenorphine provides superior analgesia compared with butorphanol in horses undergoing general anaesthesia and elective surgery, acccording to a recent study.

Following the recent licensing of buprenorphine in horses, researchers compared the analgesic and physiological properties of buprenorphine with those of butorphanol when used peri-operatively in 89 horses undergoing elective surgery at six different centers.

Horses received either butorphanol or buprenorphine after sedation with an α-2 agonist (in most cases romifidine). The clinician was blinded as to which of the two partial agonists was being used.

General anaesthesia was induced with ketamine and diazepam, reflecting a realistic clinical practice setting. The assessor recorded a score on a four-point scale for the quality of sedation following opioid administration, the quality of recovery after general anaesthesia and the degree of sedation, ataxia and perceived pain after recovery. Gastrointestinal (GI) sounds and fecal output were also recorded.

One clinic used lower doses of both buprenorphine (5 µg/kg bwt) and butorphanol (0.02 mg/kg bwt) compared with those used in other clinics (10 µg/ kg and 0.1 mg/kg, respectively). These “low” and “high” dose subgroups were compared in the statistical analysis.

During anaesthesia, no significant differences in physiological parameters, including mean arterial blood pressure, were noted between the two opioids.

Surgical conditions were recorded as excellent in more than 80% of horses in both groups, with no significant difference between them. Isoflurane requirements for maintenance of anaesthesia were unaffected by the opioid used. There was no difference in the quality or duration of recovery from anaesthesia between the two groups, at either low or high doses.

Post-operatively, pain scores were significantly improved in horses receiving buprenorphine compared with butorphanol. Of the small number of cases requiring supplementary rescue analgesia post-opera-

tively, more had received butorphanol.

There was no difference between the opioid groups in relation to post-operative sedation and ataxia. When the two subgroups of low and high doses were compared, analgesia was significantly better with buprenorphine at 10 µg/kg dose compared with butorphanol, but no difference was observed when buprenorphine was used at the lower dose. The researchers said as this part of the study was underpowered. The incidence of side-effects post-operatively, including GI disturbance, was low in both groups, but box-walking appeared a more common occurrence where buprenorphine had been used.

The most appropriate dose of buprenorphine to maximise analgesic properties while minimising side-effects warrants further investigation.

MeV

Lifting Large Animals Since 1957

For more information: Taylor PM, Hoare HR, de Vries A. A multicentre, prospective, randomised, blinded clinical trial to compare some perioperative effects of buprenorphine or butorphanol premedication before equine elective general anaesthesia and surgery. Equine Vet J 2015 June 10.

DOI: 10.1111/evj.12442 [Epub ahead of print]). http://onlinelibrary.wiley.com/doi/10.1111/evj.12442/ abstract

www.shanksvet.com • info@shanksvet.com ModernEquineVet.com | Issue 8/2015

3

cover story

Role for

MRI in diagnosing some foot pain

B

y

M

a

r

Magnetic resonance imaging

e

R

o

s

e

n

t

an accurate diagnosis, but that does not mean that all lame horses need an MRI scan,” said Dr. Dyson “All work-ups of foot pain should be thorough and follow a logical sequence,” she said. “Clinical signs are not very specific. Nerve blocks are not as helpful as we would like them to be. Radiography has limitations in some, but by no means all, cases of foot pain.”

Dr. Dyson and her team tried to tease out what particular char-

h

a

l

,

M

S

acteristics of a horse with navicular disease alone or in combination with injury of the collateral sesamoidean ligament (CSL) and/or the distal sesamoidean impar ligament (DSIL) (collectively known as the podotrochlear apparatus) are different from other causes of equine foot pain, either clinically, in their response to nerve blocks, or based on radiological assessment. They did a retrospective study of all horses examined at the AHT comparing clini-

Credit: Courtesy of Dr. Dyson

(MRI) can play a role in helping veterinarians make an accurate, definitive diagnosis of foot pain, according to Sue J. Dyson, MA, VetMB, PhD, DEO, FRCVS, head of clinical orthopedics, Centre for Equine Studies at the Animal Health Trust (AHT) in Newmarket, Suffolk in the United Kingdom.

“MRI is part of our diagnostic tools. The results of this study indicate that it is sometimes essential for

i

Dorsoproximal-palmarodistal oblique image of a left front navicular bone; lateral is to the right. There is moderate entheseophyte formation on the proximal border of the navicular bone (white arrows) at the insertion of the collateral sesamoidean ligament. There are clusters of radiolucent zones in the distal medial and distal lateral aspects of the navicular bone, distal to which are large distal border fragments (black arrows).

4

Issue 8/2015 | ModernEquineVet.com

“WHEN I TRAIN, THE LACK OF SORENESS IS AWESOME. THE MOBILITY IS THERE. I THINK OVERALL THEY JUST FEEL BETTER ON LIFELINE.”

– RUSTY GREEN ONE OF THE TOP WESTERN PERFORMANCE HORSE TRAINERS

– RON EMMONS 2-TIME NRCHA WORLD’S GREATEST HORSEMAN WINNER © K.C. Montgomery

© Becky Hanson

“LIFELINE IS THE FIRST SUPPLEMENT I’VE USED THAT COVERS SUCH A BROAD RANGE OF EQUINE HEALTH ISSUES.”

“SHORTLY AFTER TRYING LIFELINE, MY HORSES’ ATTITUDES, SOUNDNESS & HAIR COATS IMPROVED.”

“LIFELINE IS A LIFE CHANGER FOR HORSES—I HAVE NEVER SEEN A PRODUCT THAT IS ABLE TO COVER SO MANY DIFFERENT AREAS OF A HORSE.”

– CRAIG JOHNSON 15-TIME WORLD CHAMPION, NRHA MILLION DOLLAR RIDER

– CHRIS COX RFD-TV PERSONALITY, 4-TIME ROAD TO THE HORSE CHAMPION © Tammy D Reynolds

“WITHIN A FEW DAYS, LIFELINE HAD CHANGED MY HORSE’S DEMEANOR FOR THE BETTER.”

– MONICA CAETANO CHAMPION REINED COW HORSE TRAINER

– LES VOGT 15-TIME WORLD CHAMPION, NRCHA HALL OF FAME HONOREE © Primo Morales

© Primo Morales

“WITH LIFELINE, MY HORSES STAY PHYSICALLY AND MENTALLY FRESH THROUGHOUT TRAINING & SHOWING.”

SEEING IS BELIEVING.

LOOK WHO’S USING LIFELINE. LIFELINE Equine performance supplements help horses move effortlessly, breathe with ease and maintain a healthy gut. Our serum-based active ingredient BioThrive™ is multisystemic and proven to ease negative responses from stress.

To discover why these world-class horsemen use LIFELINE Equine performance supplements on their own horses, visit watchthemthrive.com.

®

RESULTS IN JUST 14 DAYS

Credit: Courtesy of Dr. Dyson

cover story

Transverse T2* weighted gradient echo high-field magnetic resonance image of the same foot as the figure on page 4. Lateral is to the right.

The collateral sesamoidean ligament (CSL, part of the podotrochlear apparatus) is enlarged and has increased signal intensity (arrows). There is loss of separation of the CSL and the deep digital flexor tendon.

cal and radiologic assessments with a diagnosis of foot pain based on MRI with or without post-mortem examination.

“All the older literature relating to navicular disease signs and response to diagnostic tests was pre-MRI and, therefore, the accuracy of the final diagnosis was uncertain, unless it was end stage disease,” she said. “We wanted to determine if there were particular characteristics that made horses with navicular disease in its various forms and injuries of other aspects of the podotrochlear apparatus different from horses with other causes of foot pain, either clinically—in their response to nerve blocks—or or based on radiological assessment.”

During the period of the study, they examined 4,618 horses of which 702 had front foot pain with a definitive diagnosis: • 62 had navicular disease, • 180 had lesions of the collateral sesamoidean ligament and/ or distal sesamoidean impar ligament,

• 69 had a deep digital flexor tendon injury, • 92 had injured their podotrochlear apparatus, including the navicular bone, and • 299 had some other form of foot pain.

The duration of lameness ranged from less than one month to more than 60 months. For more than 30% of the horses, the onset of the lameness was sudden. The results of clinical assessment were similar among all the diagnostic groups, and more than 50% of the horses’ records recorded no abnormalities other than lameness, according to the study results which appeared in The Veterinary Journal.

The clinical examination included subjective assessment of the foot conformation, digital pulse amplitudes, response to hoof testers, distention of the distal interphalangeal (DIP) joint capsule or digital flexor tendon sheath and other swellings, response to palpation, and digital manipulation and posture. Lameness was graded on a scale of 0–8 at the walk and the trot in straight lines, as well as in circles on a soft and hard surface. Radiographs, ultrasounds and MRIs were also taken.

Almost 25% of the navicular bursa cases reported a low heel or broken back foot-pastern axis. Forty-two percent of all patents had distension of the DIP joint.

More than 6% of the horses displayed lameness at the walk, 52.8% showed unilateral lameness, and 47.2% showed bilateral forelimb lameness while trotting on a firm surface. More than 32% of horses appeared lamer when on a circle than when on a straight line, the researchers said, and lungeing on a hard surface—rather than a soft

one—produced a higher lameness score in most horses.

“Overall, 62.7% of horses displayed a variable degree of lameness under the same circumstances during the period of lameness investigation,” the researchers wrote. “The consistency of the lameness during investigation (improving, worsening, variable or no change) was unrelated to diagnostic group.”

There was no statistical difference among the horses in response to nerve blocks. Between 45% and 56% of horses in all the groups showed improvement (>80%) after a palmar digital nerve block; between 76–90% showed improvement (>80%) after a palmar nerve block and 16–36% showed improvement after intra-articular analgesia of the distal interphalangeal joint and 25–75% showed improvement after analgesia of the navicular bursa. In fewer than 5% of horses, a low fourpoint block was required to improve the lameness, the researchers said.

When reviewing the radiographs, researchers were more likely to see moderate to severe evidence of navicular bone disease in horses with injuries of the CSL and or DSIL or deep digital flexor tendon than in the other groups.

The clinical exam generally could not discriminate among the causes of foot pain and the radiological scores did not accurately predict navicular bone pathology, they said. “In the majority of horses, there were no localizing clinical signs suggestive of the source of the pain,” the researchers wrote.

While clinical, radiological and ultrasonographic findings all point toward a diagnosis, MRI might provide more definitive answers, they said.

MeV

For more information: Parkes R, Newton R, Dyson S. Is there an association between clinical features, response to diagnostic analgesia and radiological findings in horses with a magnetic resonance imaging diagnosis of navicular disease or other injuries of the podotrochlear apparatus?

Vet J. 2015 Apr;204(1):40-6. doi: 10.1016/j.tvjl.2014.12.038. Epub 2015 Jan 8. http://www.ncbi.nlm.nih.gov 6

Issue 8/2015 | ModernEquineVet.com

news notes

Treatment of Equine Metabolic Syndrome An individual weight loss and exercise plan tailored to horse/owner circumstances and regular contact with the primary clinician maximized owner compliance and achieved metabolically significant levels of weight loss in the treatment of equine metabolic syndrome (EMS).

A recent study evaluated the efficacy of a weight loss and exercise plan employed by owners under veterinary guidance for treatment of EMS. Each horse underwent clinical examination, body condition scoring (BCS), adrenocorticotropic hormone (ACTH) stimulation test and a combined glucose-insulin tolerance test. Horses with pituitary pars intermedia dysfunction were not studied.

Median BCS at the start of the study was 4.5/5. For each of the 19 horses studied, an individual dietary and exercise regime was created. General recommendations included weighing all feed, feeding 1.5% bodyweight in fresh weight of hay (preferably soaked) and using a

commercial balancer to maintain sufficient levels of vitamins, minerals and protein. Specific recommendations on turnout and exercise were also devised to fit with the owner’s management system. The clinician also made several reassessments of the horse’s condition. Owners were encouraged to keep in regular contact between assessments allowing fine adjustments to be made to the diet and exercise plan where necessary. At the final assessment, the examination and blood tests were repeated.

All horses showed a reduction in BCS (median change 1/5) and 95% had a reduction in body mass. When the results of the repeated combined glucose-insulin tolerance tests were compared with results at the beginning of the study, significant decreases were observed in several measures, including basal insulin, insulin at 45 minutes, time for glucose to reach baseline, and area under the glucose curve.

MeV

For more information: Morgan RA, Keen JA, McGowan CM. Treatment of Equine Metabolic Syndrome: A Clinical Case Series. Equine Vet J 2015 June 18. [Epub ahead of print]). http://onlinelibrary.wiley.com/doi/10.1111/evj.12445/abstract

The Winning Formula for Champions

The only FDA-approved PSGAG on the market for equine intramuscular use proven to: •

STOP the destructive disease cycle

•

REVERSE degenerative joint disease

•

IMPROVE joint function

For more information on equine joint health and treatment with Adequan® i.m. (polysulfated glycosaminoglycan), please visit www.adequan.com.

American Pharoah, the 12th winner of the elusive Triple Crown®!

Owned by the Zayat Racing Stable, trained by Bob Baffert and ridden by Victor Espinoza, American Pharoah won the 141st Kentucky Derby, the140th Preakness Stakes and the 147th Belmont Stakes.

Now Available!

There are no known contraindications to the use of intramuscular Adequan® i.m. brand Polysulfated Glycosaminoglycan in horses.

Studies have not been conducted to establish safety in breeding horses. WARNING: Do not use in horses intended for human consumption. Not for use in humans.

Keep this and all medications out of the reach of children. Caution: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Each 5 mL contains 500 mg Polysulfated Glycosaminoglycan. Brief Summary Indications: For the intramuscular treatment of non-infectious degenerative and/or traumatic joint dysfunction and associated lameness of the carpal and hock joints in horses.

See Product Package Insert at www.adequan.com for Full Prescribing Information Adequan® is a registered trademark of Luitpold Pharmaceuticals, Inc. © Luitpold Animal Health, division of Luitpold Pharmaceuticals, Inc. 2015. Photo by Anne M. Eberhardt, Copyright Blood-Horse Publications used with permission. Triple Crown is a registered trademark of Triple Crown Productions LLC. AHD132 Rev. 6/2015

nutrition

Horses can absorb

omega-3 fatty acid supplements Next study to evaluate impact of omega-3 fatty acids on performance B y

K a t h l e e n

O g l e

to benefit humans, cats and dogs with cardiovascular disease, osteoarthritis and various skin diseases. Investigators are now studying whether horses—who are often very deficient in omega-3 fatty acids—can achieve benefit from a diet augmented by the nutritional supplement.

Lisa A. Fortier, DVM, PhD, ACVS, professor of large animal surgery at Cornell University College of Veterinary Medicine, Ithaca, NY, discussed the use of omega-3 fatty acid supplements for horses at the Cornell Ruffian Equine Special-

Comparison of omega-3 supplements for horses Product

Supplement Form

Omega-3 Source

Total Omega-3 (g/Daily Dose)

Per Day Cost

Cost (1 Month)

Veterinarian Recommended Nutraceuticals*

Top dressing

Fish oil

15

TBD

TBD

Ascenta Equine Omega-3 Fish Oil

Top dressing

Fish oil

6.8

$1.89

$56.95

Drs Foster and Smith Equine Omega-3 Fish Oil Supplement

Top dressing

Fish oil

8.9

$1.51

$49.99

Nutramax Welactin Equine

Top dressing

Fish oil

8.5

$1.48

$47.29

Smartpak Smart Omega-3 Ultra

Powder

Fish oil, flaxseed

7

$1.03

$28.95

MVP Equine OMEGAS

Pellet

Flaxseed, coconut oil

0.075

$0.92

$29.25

Triple Crown Omega Max

Powder

Flaxseed

35.–5

$0.76– $2.00

$50.00

*Cost per day and cost per month will be dependent upon outcome of trial.

Source: Lisa A. Fortier, DVM, PhD, ACVS

8

Issue 8/2015 | ModernEquineVet.com

Shutterstock/Ratchapol Yindeesuk

Omega-3 fatty acid supplements have been shown

ists Anniversary Celebration, June 25, in Elmont, NY.

More answers

She performed the research because the supplement industry is not regulated by the FDA or the USDA. Even though there are many omega-3 fatty acid supplements available for horses, it was not known if the horses were even able to absorb the nutrient and at which dosage and frequency the supplements should be administered. Now, there are more definite answers, she said.

“You can take or go buy as many of these as you want,” Dr. Fortier said. “No one regulates the industry.

You have no idea when you go to the feed store that what you actually buy, what it says on the label, is actually what you are getting.”

Even though there are many omega-3 fatty acid supplements available for horses, whether they can absorb the nutrient was unknown before this study.

She added that unfortunately this was also the case for humans who take these supplements.

Supplements can be expensive, she added. Purchasing supplements from a reputable company may give you some assurance of the product's quality.

To determine whether normal horses were able to absorb the omega-3 fatty acids in the supplements, Dr. Fortier collaborated with Cazenovia College’s New York State Center for Equine Business Management in Cazenovia, NY, and the Equine Rehabilitation Center at Morrisville State College, Morrisville, NY, where they enrolled 50 horses—25 at each facility—in the study.

Most of the horses at Cazedonia College were Warmblood hunter jumpers, and most of the horses at Morrisville College were Thorough-

ModernEquineVet.com | Issue 8/2015

9

NUTRITION

breds in training, she said.

Horses were given either 7.5-g or 15-g doses of the omega-3 fatty acid supplement, which was administered with the horses’ feed.

The supplement smells like salmon “stinks,” Dr. Fortier said. Yet, the horses ate it every day for 12 weeks and not one horse refused its food.

Larger doses

Blood samples were taken at baseline, 6 weeks and 12 weeks, and they were tested by Veterinarian Recommended Diagnostics using the iFATS (Inflammatory Fatty Acid Target Score) test. The iFATS measured 24 different fatty acids providing a fatty acid profile for each horse, Dr. Fortier said.

According to Dr. Fortier, the horses’ fatty acid profiles improved with both doses, with the omega-6 to omega-3 ratio scores declining and the omega-3 fatty acid scores increasing at 6 weeks and 12 weeks.

The biggest improvement in scores were seen with the larger 15-g dose.

The iFATS depicts a score of <2 as undesirable (deficient); a score of 2–12.9 is intermediate; and a score > 12.9 is desirable.

Owners of horses that receive scores <2 are given the recommendation to supplement their horses’ diet with an omega-3 fatty acid in the form of EPA and DHA.

The horses' fatty acid profiles improved after omega-3 fatty acid supplementation, with the biggest improvement shown with the larger 15-g dose.

Whether the fatty acid contains EPA and EHA “is really dependent upon the type of omega-3 fatty acid that you give,” Dr. Fortier said. “Giving flaxseed is not going to give DHA and EPA but giving salmon will, depending upon the type of salmon.”

With confirmation that horses can indeed absorb omega-3 fatty acid supplements, Dr. Fortier is enrolling horses in an interventional study to measure the impact of omega-3 fatty acid supplementation on exercise and recovery.

Treatment

Using a treadmill, the horses will

be run to exhaustion and then the investigators will take blood samples to measure iFATS as well as oxidative stress markers such as lactate, lipid hydroperoxides, total glutathione, glutathione peroxidase, alpha tocopherol, beta carotene and retinol. The horses’ diets will be supplemented with omega-3 fatty acids (15 g/day) for six weeks.

“We know that it’s absorbed, we know what our target measure is, and we want to know that this makes a physiologic difference in horses,” she said.

Future studies in horses may look at the impact of omega-3 fatty acid supplementation on inflammation and osteoarthritis.

Veterinarian Recommended Solutions is offering the iFATS test for free. Tests must be ordered through a veterinarian. If the results indicate less than desirable levels of omega-3 fatty acids, the test is free with the purchase of Equine Omega Benefits. If the test comes back with a less than desirable result and the product is not purchased, the pet owner pays for the test. If the test results are in the intermediate range, the test is free. To request the test, contact Steve Mehler, DVM, DACVS, chief medical officer of Veterinarian Recommended Solutions, at MeV smehler@vrshealth.com.

Sign up today * We promise not to bombard you with emails. Just a notice when new information is available.

10

Issue 8/2015 | ModernEquineVet.com

Send us your email address

Respiratory

Advances in

Upper Airway Surgery Ultrasonography can identify horses with impending disease. y

P

a

u

l

When Norm G. Ducharme,

DVM, MSc, the James Law Professor of Surgery at Cornell University, came across a textbook written in 1600 that described recurrent laryngeal neuropathy in the horse, the treatment involved red wine. The textbook didn’t specify whether the wine was for the horse or for the veterinarian, but the horse kept roaring anyway, he said.

Thankfully, the treatment for this old disease has advanced somewhat during the past 400 years.

During an event marking the first anniversary of the Cornell Ruffian Equine Specialists, located across the street from the backstretch of Belmont Park, Dr. Ducharme brought the veterinarians in attendance up-to-date on recent advances in upper airway surgery.

Assessment

“The muscle of the larynx is a marker for what is happening in the upper airway of a horse,” Dr. Ducharme said. “With ultrasonography, we can identify horses with impending disease, and we can tell whether the cause was trauma (or the result of a misinjection), or the

B

a

s

i

l

i

o

naturally occurring disease.”

On ultrasound, the affected muscle will appear whiter due to increased reflection of the ultrasonographic waves. This can shed light on what is happening to the muscle fibers and offer insight to the cause and timing of onset of disease.

“We can also measure the size of the muscle,” Dr. Ducharme noted.

“We can tell if disease is present or we can make a prediction about whether the horse will have some disease in the future.” Dr. Ducharme and his colleagues performed studies involving nearly 100 horses, and the results showed that if more than 20% atrophy is present, most horses will have some sort of collapse.

Computer modeling is also being used to predict the change of the air flow pattern in the horse. “We can see what the pressures are in front of the larynx. We can tell why horses with an obstruction on the left side will also get tissue sucked in from the right side,” he explained. “This is predictable with computer modeling, which has allowed us to tailor the treatment for these horses.”

Dr. Ducharme stressed the importance of performing a dynamic

Images courtesy of Dr. Ducharme

B

Top: Before surgery at rest notice the left side of the larynx - right side of picture - is lower than opposite side. Middle: Before surgery at exercise the cartilage collapse even more on the horse left side- right on picture.

Bottom: At exercise horse number two ModernEquineVet.com | Issue 8/2015

11

Respiratory

examination in roaring horses. A clinician can see different forms of laryngeal collapse after the horse has been running on the track or on a treadmill.

“Horses can make noise and have an airway obstruction that isn’t necessarily laryngeal hemiplegia,” he said. “There are other causes of obstruction that can be missed without a dynamic examination. With the technology we have, these examinations can be performed in almost every horse.”

Treatment

Images courtesy of Dr. Ducharme

Dr. Ducharme has moved to performing a standing tie-back procedure in many horses with recurrent laryngeal neuropathy. The move was partly because of the risk of anesthesia in larger horses.

“We also found that you can visualize the cricoarytenoidal joint just as well while the horse is standing,” so the surgery is actually easier to perform standing than the traditional lateral recumbency, he explained.

The most important value of “standing tieback” is that the surgeon can more precisely positioned the paralyzed cartilage, so as to maximize the opening while

minimizing the risk of complications. This is because the surgeon has to decide where to affix the cartilage so that the horse can pass enough air and still avoid the risk of postoperative cough. If the horse is lying on its side, with a tube in his larynx (needed to provide anesthesia), this is difficult to do precisely. If the horse is standing, the surgeon can tell exactly where s/he needs to work without other structures getting in the way, so the treatment is much more precise, he explained.

In horses with disagreeable temperaments or in situations where a combined orthopedic/throat procedure is being performed, the standing tie-back is not advised.

The technical aspect of the procedure is also changing. “When we tie two pieces of cartilage during this procedure, there is little strength to the tissue,” Dr. Ducharme said. “I like to say that the procedure either works or the horse failed to respond to proper treatment.”

During the past couple of years, the use of a titanium button has been introduced, which provides a marked advantage for stability throughout the upper airway.

The Near Future

The use of a pacemaker for laryngeal reinnervation was first brought to equine medicine in 1989, but the procedure has begun to change and may soon be brought back into use. A French ENT surgeon (Dr. Jean-Paul Marie) has performed laryngeal transplantation in 27 humans, and Dr. Ducharme and others are working with him to bring that procedure to equine medicine.

“The laryngeal pacemaker is coming back to the forefront, either as a way to condition the muscle to receive a transplanted nerve or to accelerate the growth of nerve into the muscle,” he reported. “The nerve itself is pruned with certain cuts to allow for the sprouting of more of the axon through the muscle.

The most recent work along these lines involved ALS in rats.

Researchers have been using electrical stimulation to increase axonal growth or nerve regrowth.

Laryngeal pacemaker has been used in 86 horses to date, but things are still in the experimental phase. Work continues as new information comes into view over MeV the horizon.

Left: After surgery notice the left side of the larynx - right side of picture - is higher than opposite side and the level before surgery. Right: After surgery horse no 2.

12

Issue 8/2015 | ModernEquineVet.com

news notes

Riding a horse is far more complex than riding simulators Flight simulators for the training of air pilots work well. But what about riding simulators? Although the first horse simulator was used at the French National Equestrian School in Saumur in the 1980s, riding simulators for dressage, show jumping, polo or racing have become available only recently. They look like horses and respond to the aids of the rider through sensors which measure the force exerted by the reins and the rider’s legs. Using a screen in front of the simulator, the rider immerses himself into a virtual equestrian world.

psychologically less demanding for riders,” said Dr. Ille.

Heart rate data indicate that the training on a horse had a more pronounced stimulatory effect on the riders’ sympathetic nervous systems compared with the training on the simulator. Sympathetic activity is known to increase the body’s performance potential in sportive activities.

Analysis of the stress hormone cortisol in saliva collected from the riders also suggests a stress reaction on the simulator. “This may be due to a novel experience for the riders. Participants in the study had never trained on a simulator before, but were well accustomed MeV to working with horses,” Dr. Ille suggested.

Riding a horse is more of a challenge than riding a simulator.

Aimed at competitive sports

Riders and jockeys use simulators to repeat movement sequences, improve their position in the saddle or simulate the finish of a race, but they also train to avoid injuries when falling off a horse. Jockeys also use riding simulators to regain their physical fitness after injuries. A riding simulator always responds in the same way and thus allows standardised training programs,” said Natascha Ille, Mag. Med. Vet, from the University of Vienna, College of Veterinary Medicine (Vetmeduni Vienna).

Dr. Ille and her co-workers from the Graf Lehndorff Institute for Equine Science, a joint research unit of the Brandenburg State Stud and Vetmeduni Vienna, tested the response of 12 riders in a show jumping course. They compared the riders’ stress hormones, heart rate and heart rate variability when riding a horse against riding a simulator.

The riders’ heart rate was higher when riding a horse than during simulator-based training. “A horse is the bigger challenge compared with a simulator. The movement characteristics of a horse are more complex and the response of a horse in a given situation is only partially predictable. Riding a simulator is thus physically and

Image courtesy of Vetmeduni Vienna

Riding a horse is more demanding

The stimulator creates a virtual equestrian world for the rider, but it is not the same as riding a live horse.

For more information: Ille N, von Lewinski M, Aurich C, et al. Riding simulator training induces a lower sympathetic response in riders than training with horses.

J Equine Vet Sci. 2015;35(8):668–672 doi:10.1016/j.jevs.2015.06.018 ModernEquineVet.com | Issue 8/2015

13

behavior

I can see it in your

face Just as humans do, horses use their nostrils, lips and eyes to alter their facial expressions in a variety of social situations. So yes, that horse is laughing at you!

pressions to humans and chimps, according to new research from the University of Sussex in the United Kingdom.

Mammal communication researchers have shown that horses use their muscles’ underlying various facial features—including their nostrils, lips and eyes— to alter their facial expressions in a variety of social situations, just as humans do.

The findings suggest evolutionary parallels in different species in how the face is used for communication. Research has already shown that cues from the face are important for horses to communicate, by developing an objective coding system to identify different individual facial expressions on the basis of underlying muscle movement.

The Equine Facial Action Coding System (EquiFACS), as devised by the Sussex team with researchers at the University of Portsmouth and Duquesne University, identified 17 discrete facial movements in horses. This compares with 27 in humans, 13 in chimps and 16 in dogs.

“Horses are predominantly visual animals, with eyesight that's better than domestic cats and dogs, yet their use of facial expressions has been largely overlooked. What surprised us was the rich repertoire

14

Issue 8/2015 | ModernEquineVet.com

Shutterstock/Studio 37

Horses share some surprisingly similar facial ex-

Credit: Jennifer Wathan

of complex facial movements in horses, and how many of them are similar to humans.

“Despite the differences in face structure between horses and humans, we were able to identify some similar expressions in relation to movements of the lips and eyes,” said Jennifer Wathan, a doctoral researcher at the University of Sussex.

“What we’ll now be looking at is how these expressions relate to emotional states.”

The researchers analyzed video footage of a wide range of naturally occurring horse behaviors to identify all the different movements that horses make with their face. They also carried out an anatomical investigation of the facial muscles that underpin these movements. Each individual facial movement that was identified was given a code.

“It was previously thought that, in terms of other species, the further away an animal was from humans, the more rudimentary their use of facial expressions would be,” said Karen McComb, PhD, professor at the University of Sussex.

Horses use similar facial muscles to humans, suggesting an evolutionary parallel in how horses and humans use the face to communicate.

“Through the development of EquiFACS, however, it’s apparent that horses, with their complex

and fluid social systems, also have an extensive range of facial movements and share many of these with humans and other animals. This contributes to a growing body of evidence suggesting that social factors have had a significant influence on the evolution of facial expression.”

She added that a systematic way of recording facial expressions would have a wide range of uses.

“With EquiFACS, we can now document the facial movements associated with different social and emotional contexts and thus gain insights into how horses are actually experiencing their social world,” she said, adding that the information should enhance “our understanding of social cognition and comparative psychology. The findings should ultimately provide important information for veterinary and animal welfare practices.”

MeV

EquiFACS can document the facial movements associated with different contexts and gain insights into how the horse experiences its social world. Click here to watch.

 For more information: Wathan J, Burrows A, Waller BM, McComb K. EquiFACS: The equine Facial Actin Coding System. PLOS ONE, 2015 DOI: 10.1371/journal. pone.0131738 http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0131738 ModernEquineVet.com | Issue 8/2015

15

practice management

Things Are Looking Up for the

Equine Industry The equine industry has found

stability and shows positive signs of growth, especially among young adult horse owners and event participants, according to results of a survey by American Horse Publications (AHP) sponsored by Zoetis.

The survey included responses from more than 10,662 horse owners.

Among the highlights, the 2015 AHP Equine Industry Survey sponsored by Zoetis shows: • For 2016, 88.6% of respondents expect to own or manage the same number of horses or more horses.

• This year, 93% of respondents plan to enter the same or more competitions than last year, and 95.1% expect to compete in the same or more events in 2016.

• A high number of respondents (84.7%) rely on their veterinarians for vaccination advice, and respondents are increasingly relying on veterinarians for deworming advice.

“It appears the industry is beginning to recover from the Great Recession of 2008, as indicated by the percentage of respondents participating in the industry, either through owning/managing horses or competing with them, at the same or greater levels than three years ago,” said Jill Stowe, PhD, associate professor of agricultural economics at the University of Kentucky, who analyzed the data and consulted on the results.

The survey was conducted from January 6 through April 1, 16

Issue 8/2015 | ModernEquineVet.com

2015. It sought to gauge participation trends and management practices in the U.S. equine industry, to identify critical issues facing the industry as perceived by those who own or manage horses, and to better understand issues pertaining to horse health and nutrition.

AHP conducted similar surveys in 2012 and 2010. AHP is a nonprofit professional association dedicated to promoting excellence in equine media and better understanding and communication within the equine publishing industry.

Industry Stability

The 2015 survey results show 70.6% of respondents own or manage the same number of horses they did last year, suggesting a continued increase in overall industry stability. In addition, 20.7% of respondents expect to own or manage more horses in 2016, while 11.4% expect to own fewer horses. In the 2012 survey, only 18.7% said they expected to own or manage more horses the following year, and 14.7% expected to have fewer.

Looking at horse ownership by age, the future appears bright for the equine industry, with 22.1% of respondents ages 18 to 24 reporting they own or manage more horses in 2015 than they did in 2014, while only 7.6% of respondents age 65 or over reported owning or managing more horses. This pattern is consistent with expectations of horse ownership in 2016, as 36.2% of respondents ages 18 to 24 said they expect

to own or manage more horses than they did this year.

Additionally, there appears to be stability in the number of competitions respondents expect to attend this year and next year. Similar to the 2012 survey, most of the increase in competitions is among younger age groups.

Horse Health Care

Respondents continue to identify veterinarians as integral to horse health decisions, including vaccinations and deworming.

Veterinarians continue to have a strong influence over vaccination decisions, with 84.7% of respondents saying they discuss with their veterinarian what vaccinations their horse should receive.

Those discussions most often include vaccinating for West Nile virus, Western and Eastern equine encephalomyelitis, equine herpesvirus and equine influenza.

Most respondents vaccinate once a year (58% to 72%, depending on the antigen). However, about 20% of respondents vaccinate against these diseases twice a year. Vaccination also presents an opportunity for veterinarians to discuss the American Association of Equine Practitioners (AAEP) vaccination recommendations with their clients, as just 30% of respondents said they reviewed these recommendations with their veterinarian.

It appears the influence of veterinarians on deworming approaches is increasing, as there was a slight

increase compared with previous surveys in the percentage of respondents who had a fecal egg count (FEC) conducted and who said their veterinarian is involved in developing their deworming schedule.

Rotational deworming was the most common approach used (55.3%), despite recent recommendations from AAEP to conduct FECs and deworm based on results, which came in second (38.2%), according to the results. Less than half of respondents (47.5%) indicated their veterinarian recommended an FEC. Nearly half (46%) of horse owners deworm their horses four to six times per year. Almost 80% of respondents said parasite drug resistance was an issue of concern, similar to 2012.

Overwhelmingly, respondents deworm their horses themselves, at 88.6%, which was nearly identical to the 2012 survey results. But about half of the respondents (48%) indicated their veterinarian is involved in developing their horses’ deworming schedules. This trend has continued to increase, from 15.7% in 2010 to 44.3% in 2012.

A slight decline in the number of insured horses continues to be a trend in 2015 survey, with just 21.7% of respondents indicating their horses were insured. This presents an opportunity for equine veterinarians to make their clients aware of insurance and to reinforce the need for preventive care, including additional diagnostic and treatment options.

Relationship with the Horse

Based on a new question this year, the survey results reflected the complex relationship between humans and horses. Respondents were most likely to view their horses as family members 67.4%), companion animals (62.7%), performance partners

In your opinion, what are the top three issues facing the equine industry?

Unwanted horses and what to do with them Cost of horse keeping Overbreeding Owners who don't understand horses Loss of trails and riding areas Competition for open space Horses that aren't trained appropriately Horses going to slaughter Not having the option of slaughter in the U.S. Lack of marketing about equestrian events Ineffective welfare laws Lack of a unified voice in Washington, DC The possibility of slaughter houses re-opening Overburdened welfare groups Disease outbreaks Lack of educational material on horses 0.0%

(57.6%) and/or best friends (55.9%).

A smaller percentage of respondents viewed their horses as an investment (22.4%), livestock animal (21.1%) or employee (7.8%).

Results also show an estimated one of every three horses owned/ managed by respondents is idle, retired or otherwise not working.

The Unwanted Horse

As in the 2010 and 2012 surveys, the issue of unwanted horses (and what to do with them) remains the most significant challenge facing the industry today; however, the percentage of respondents identifying the issue has been declining (62.9% in 2010, 55.8% in 2012 and 53.7% in 2015). The cost of horsekeeping (47.1%) and overbreeding (37.3%) continue to be important issues, but land-related issues, such as loss of riding areas and competition for open space, are becoming increasingly important.

Concern over disease outbreak

10.0%

20.0% 30.0%

40.0% 50.0%

60.0%

remains low among horse owners, as just 5.8% indicated disease outbreaks were an issue. While concern is low, veterinarians can help horse owners lower their risk of infection by advising vaccine protocols to meet horses’ risk levels, including travel and show requirements, such as following the vaccine requirements of the United States Equestrian Federation (USEF).

About the Survey

The 2015 survey was limited to those who currently own or manage at least one horse, are 18 years of age or older and live in the United States.

The survey collected 11,307 responses, of which 10,662 responses were useable.

“As a sponsor of the survey, Zoetis is proud to bring additional insight to the equine industry on topics horse owners and managers find important, so we can work together as partners,” said Katherine Russo, marketing manager, equine vaccines.

MeV ModernEquineVet.com | Issue 8/2015

17

news notes

Diagnosing Lyme Disease in Horses Is Difficult

CDC/Janice Haney Carr

By Louisa Shepard Most horses in the Mid-Atlantic region show evidence of exposure to Borrelia burgdorferi, the bacterium that causes Lyme disease. The vast majority of those exposed horses do not develop clinical signs of disease. However, a small number of infected horses will develop disease of the nervous system, termed Lyme neuroborreliosis.

Diagnosis of equine Lyme neuroborreliosis is often elusive and the disease provokes more questions than answers: What signs do horses with Lyme disease show?

What test can be used to diagnose the disease? How should test results be interpreted?

New Bolton Center veterinarians, led by Dr. Laura Johnstone, a former resident in Internal Medicine, sought to answer some of these questions by reviewing the medical records of horses that had histologic findings consistent with previous reports of Lyme neuroborreliosis in both horses and humans. Amy L. Johnson, DVM, assistant professor of Large Animal Internal Medicine and Neurology, also participated in the research.

The study included 16 horses that were patients at New Bolton Center from 2004 to 2014. Most of the horses were ataxic and showed cranial nerve deficits such as difficulty eating, difficulty breathing, tremors of the muzzle and poor tongue tone. Behavioral changes, muscle wasting, neck stiffness and uveitis (eye inflammation) were also common. Only a couple

of the horses were lame, and one horse had a heart rhythm abnormality.

Results of diagnostic tests were variable. Only about half of the horses were positive for Lyme on a blood test. The fluid that surrounds the spinal cord was analyzed in 13 of the 16 horses. Some of the horses had normal cerebrospinal fluid (CSF) while others showed evidence of inflammation. Testing the CSF using polymerase chain reaction, a test that looks for B. burgdorferi DNA, was negative in 7 of 7 horses that were tested.

This study demonstrates the poor reliability of diagnostic tests for Lyme neuroborreliosis in horses.

Whether negative or positive in blood or CSF tests, a horse may have Lyme disease. However, what appeared to be a frequent feature among these horses was the presence of cranial nerve deficits and uveitis.

MeV

To learn more about New Bolton Center's Comprehensive Equine Lyme Disease Evaluation Package, click here.

This digitally colorized scanning electron micrograph depicts a grouping of numerous Gram-negative, anaerobic, Borrelia burgdorferi bacteria, which had been derived from a pure culture.

18

Issue 8/2015 | ModernEquineVet.com

Keep Up Your Guard for West Nile Virus

For more information: Day JF, Tabachnick WJ, Smartt CT. Factors that influence the transmission of West Nile Virus in Florida J Med Entomol 2015 DOI: http://dx.doi.org/10.1093/jme/tjv076 [Epub ahead of print on July 1}.

specific group of people over a particular period of time.”

An “outbreak” is characterized as sporadic individual cases or small clusters of disease cases. It’s easier to predict widespread epidemics than small clusters. MeV

Watch "Silencing the Buzz "



GAINESVILLE, Fla.—While Florida has never experienced a serious West Nile virus (WNV) epidemic, UF/ IFAS scientists caution vigilance about this dangerous mosquito-borne illness.

They continue to study ways to monitor and control this virus. Researchers track rainfall, groundwater levels, mosquito abundance, wild bird populations and viral transmission to animals, including horses and sentinel chickens, noting when mosquito infection rates reach the levels that can infect humans.

WNV was first detected in the United States in New York City in 1999 and in Florida in 2001. The environmental conditions that favor WNV transmission in Florida include very dry winter and early spring months, followed by heavy rainfall and short periods of drought, usually 10 to 14 days, in the late spring and early to midsummer months.

Low winter temperatures also help to predict epidemic risk, especially in south Florida, said Jonathan Day, PhD, a professor at UF/IFAS Florida Medical Entomology Laboratory in Vero Beach. Years when exceptionally cold periods were reported in south Florida, such as 1977 and 1989, were followed by mosquito-borne virus epidemics.

A mosquito known as Culex nigripalpus Theobald spreads WNV, St. Louis encephalitis virus and Eastern equine encephalitis virus in Florida. Environmental factors, especially rainfall, limit where and how often this mosquito lays its eggs and how often it takes blood from birds. So Florida has reported only small outbreaks of WNV, according to a new paper by UF/ IFAS scientists.

“However, historical epidemics of St. Louis encephalitis in Florida alert us to the eventual possibility of a widespread West Nile epidemic if and when the important environmental factors line up,” said Dr. Day. Dr. Day urged government agencies responsible for arboviral surveillance in Florida to continue to aggressively monitor the state for mosquito-borne viruses.

Confusion sometimes surrounds the terms “outbreak” and “epidemic” when it comes to predicting arboviral transmission, he said. According to the Centers for Disease Control and Prevention, an “epidemic” is defined as “the occurrence of more cases of disease than expected in a given area or among a

UF/IFAS researchers are monitoring Culex nigripalpus Theobald, seen here, to make sure it doesn't spread West Nile virus. The state has not experienced a serious epidemic of WNV, but UF/ IFAS scientists urge continued vigilance to keep the disease at bay.

Photo credit

ASPCA Grants $200,000 to Equine Rescue Groups to Assist Retired Racehorses The American Society for the Prevention of Cruelty to Animals (ASPCA) granted $200,000 to 26 equine rescue groups across the country in recognition of their efforts to assist retired racehorses.

The grants were awarded as part of the ASPCA Rescuing Racers Initiative, which aids in the rescue and rehabilitation of retired racehorses. Now in its sixth year, the program gives retired racers a new lease on life by preparing them for lives off the track.

“Six years ago, the ASPCA received an anonymous donation to launch the Rescuing Racers Initiative, and with the help of our generous donors, we have been fortunate enough to continue providing much-needed grants to the dedicated equine rescue groups across the country who offer sanctuary and after-care to retired racers,” said Jacque Schultz, senior director of the ASPCA Equine Fund. “We received a record number of applications this year, making the final selection the most difficult to date. These groups are credentialed and provide critical resources to horses, saving them from ending up at livestock auctions and slaughterhouses, and the ASPCA is honored to assist them in their efforts to protect horses.”

Selected recipients include a wide range of equine rescues from 12 states, who will each be awarded a grant ranging from $5,000–$15,000 to help increase their capacity for rescuing more horses. This year’s grants primarily focused on training and rehabilitation costs, including veterinary care, therapeutic shoeing, and lay-up time to help horses recover from career-ending injuries.

In 2014, the ASPCA awarded over $1.1 million in grants to support 169 MeV equine rescues and sanctuaries across the country.

ModernEquineVet.com | Issue 8/2015

19

The Modern

Equine Vet

Reach your veterinarians wherever they are, whenever they want.

FOR ADVERTISING RATES AND INFORMATION, EMAIL Robin Gellar