The Modern Equine Vet October 2016

The Modern

Equine Vet www.modernequinevet.com

5 Tips

for the Ultrasound Stifle Exam

Vol 6 Issue 10 2016

Homefield Advantage in Wound Infections Equine Grass Sickness Oh No: Screwworm's Back Technician Update:

Managing Colic in a Minature

Table of Contents

Orthopedics

5 Tips for the Ultrasound

8 Stifle Exam

Cover photo: Shutterstock/Olga_i

wound care

Home field advantage in wound infections ....................................................................... 4 Infectious Diseases

Better understanding of equine grass sickness ....................................................................10 Screwworm found for first time in 30 years ........16 technician update

Colic in a Young Miniature Horse ..............................12 News

Glucose challenge can identify insulin dysregulation in unfasted ponies .............................. 3 New client app available...............................................11 Equioxx tablets now available....................................17 advertisers Shanks Veterinary Equipment.................................. 3 Merck Animal Health.................................................. 5

Standlee Premium Western Forage......................... 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 notes

Glucose Challenge Can Identify Insulin Dysregulation in Unfasted Ponies Testing for insulin dysregulation, which is recommended in horses at risk for laminitis, can be a challenge for horses that are turned out 24/7 because they cannot easily be fasted.

Removing them from the pasture to the stable can be stressful, which could influence the oral sugar test (OST), according to recent research out of the United Kingdom.

So, the researchers set out to see if the OST could be relevant for unfasted ponies. Ten native pony mares were subjected to four OSTs, two fasted overnight and two fed (left out at pasture). Blood samples for measurement of serum insulin concentration were taken before oral administration of 0.15 mL/kg of corn syrup and at 30, 60, 75, 90 and 120 minutes, insulin concentrations were measured using a radioimmunoassay.

of dichotomous interpretation, i.e. whether ponies were defined as having insulin dysregulation or not. Within this context there was good agreement between fasted and fed results within individual ponies. Therefore, a non-fasted test will still be likely to diagnose whether insulin dysregulation is present, but repeating the test to monitor changes in insulin concentrations in an individual may not be very reliable.

Peak insulin concentrations were recorded most commonly at 30 minutes in both fasted and fed conditions, with the majority of the rest occurring at 60 minutes.

If fasting before an OST is not possible, the test is still likely to identify insulin regulation/dysregulation. The optimal window for sampling is up to 60 minutes.

MeV

Courtesy of the Equine Veterinary Journal

Lifting Large Animals Since 1957

Testing in unfasten ponies will likely diagnose whether insulin dysregulation is present, but repeating the test to monitor changes in insulin concentrations in an individual may not be very reliable.

There were significant differences between the insulin response under fasting and fed conditions. Fasting exacerbated the insulin response to sugar.

However, tests under both fasting and fed conditions had similar reliability. Additionally, although insulin values tended to differ fairly widely at the same time point within the same individual, and hence repeatability between individual OSTs was poor, the results of fasted and fed tests were similar in the context

For more information: Knowles EJ, Harris PA, Elliot J, Menzies-Gow NJ. Use of the oral sugar test in ponies when performed with or without prior fasting. Equine Vet J. 2016 Sept. 5. doi:10.1111/evj.12607 http://onlinelibrary.wiley.com/doi/10.1111/evj.12607/full

www.shanksvet.com • info@shanksvet.com ModernEquineVet.com | Issue 10/2016

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wound

Getting—and Keeping—the

Home Field Advantage in Wound Infections B

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ly, the ambient fecal contamination can harbor aerobes, anaerobes and most of the gram-negative bacteria.

This can have a powerful impact on wounds of the distal limb, for example. A penetrating wound of the abdomen or perineal area can lead to contamination from compromised bowel or intestines. Mucus can act as an ideal environment for endogenous bacteria to penetrate wounds of the oral cavity or the upper airway.

Hazards Are Numerous

“The solution to pollution is dilution,” said Dr. Orsini, quoting an old adage. “Delivering 10-15 PSI of copious amounts of physiologic saline, lactated Ringer’s solution or Hartmann’s solution to all parts of the wound is critical. You may find that you have to open some chronic wounds to get the fluids deeper into the tissue.”

Dr. Orsini also recommended repeating the lavage, as well. Lavaging once is wonderful, but repeating the lavage daily for several day—and then every other day— can knock the number of bacteria down to a level where the body can clear it on its own.

Courtesy of Dr. James Orsini

Biofilms

Delivering copious amounts of solution to all parts of the wound is critical.

Multidrug resistant infec-

tions are still relatively uncommon in the general equine population, aside from hospitalized horses. The threat still looms, however, and James A. Orsini, DVM, DACVS, recommended veterinarians begin to anticipate infections that have few good antibiotic options.

“We know the players are the bacteria, and the field is the wound,” he said. “We need to maximize local conditions and the resources

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that are going to determine the outcome of the game. Instead of relying on antibiotics as the primary means of wound management, we need to look at the big picture— one that includes the wound and the surrounding environment.”

Extensive Contamination

The first step is to take a look at the local environment.

When a horse is confined to a stall that is cleaned once or twice dai-

Bacterial biofilms are gel-like substances that provide a secure attachment for bacteria and a stable environmental where they can set up shop (see Biofilm Timeline). They are not a new discovery, but their importance in wound care has only recently come to the forefront.

“Many times, clinicians don’t see the horse until the wound is more than 4-6 hours old,” Dr. Orsini said.

“By that time, colonization has already occurred. One of the reasons veterinarians have so many problems with chronic wounds is that we’re often too late to the table.”

The films are persistent and resistant. They are normally microscopic, but a well-rooted biofilm can be seen as a shiny coating or a

The Science of Convenient Protazil® (1.56% diclazuril) is the only FDA-approved alfalfa-based top dress antiprotozoal pellet for the treatment of EPM. • Equine Protozoal Myeloencephalitis (EPM) is a serious neurological disease that can strike anytime, anywhere. Make treatment easy with Protazil® • Safe and accurate dosing with a calibrated scoop • Easier to use than paste, less stress for you and your horse • Rapid absorption — no loading dose required1 Now that’s convenient.

Ask your veterinarian for Protazil®.

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Use of Protazil® (1.56% dicazuril) is contraindicated in horses with known hypersensitivity to diclazuril. Safe use in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. The safety of Protazil® (1.56% dicazuril) with concomitant therapies in horses has not been evaluated.

See related page in this issue for details. For use in horses only. Do not use in horses intended for human consumption. Not for human use. Keep out of reach of children.

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1

Hunyadi L, Papich MG, Pusterla N. Pharmacokinetics of a low-dose and DA-labeled dose of diclazuril administered orally as a pelleted top dressing in adult horses. J of Vet Pharmacology and Therapeutics (accepted) 2014, doi: 10.111/jvp.12176. The correlation between pharmacokinetic data and clinical effectiveness is unknown

wound ANTIPROTOZOAL PELLETS

(1.56% diclazuril)

FOR ORAL USE IN HORSES ONLY For the treatment of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona in horses.

CAUTION Federal (U.S.A.) law restricts this drug to use by or on the order of a licensed veterinarian.

NADA #141-268 Approved by FDA DESCRIPTION Diclazuril, (±)-2,6-dichloro-α-(4-chlorophenyl)-4-(4,5 dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl) benzeneacetonitrile, has a molecular formula of C17 H 9 CI 3 N4O2, a molecular weight of 407.64, and a molecular structure as follows:

Weight Range of Horse (lb) 275 - 524 525 - 774 775 - 1024 1025 - 1274

mLs of Pellets 20 30 40 50

Weight Range of Horse (lb) 1275 - 1524 1525 - 1774 1775 - 2074 -

Courtesy of Dr. James Orsini

Diclazuril is an anticoccidial (antiprotozoal) compound with activity against several genera of the phylum Apicomplexa. PROTAZIL® (diclazuril) is supplied as oral pellets containing 1.56% diclazuril to be mixed as a top-dress in feed. Inert ingredients include dehydrated alfalfa meal, wheat middlings, cane molasses and propionic acid (preservative).

INDICATIONS PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets are indicated for the treatment of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona in horses.

DOSAGE AND ADMINISTRATION Dosage: PROTAZIL® (1.56% diclazuril) is administered as a top dress in the horse’s daily grain ration at a rate of 1 mg diclazuril per kg (0.45 mg diclazuril/lb) of body weight for 28 days. The quantity of PROTAZIL® necessary to deliver this dose is 64 mg pellets per kg (29 mg pellets/ lb) of body weight.

Administration: To achieve this dose, weigh the horse (or use a weigh tape)). Scoop up PROTAZIL® to the level (cup mark) corresponding to the dose for the horse’s body weight using the following chart: mLs of Pellets 60 70 80 -

One 2-lb bucket of PROTAZIL® will treat one 1100-lb horse for 28 days. One 10-lb bucket of PROTAZIL® will treat five 1100-lb horses for 28 days.

CONTRAINDICATIONS Use of PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets is contraindicated in horses with known hypersensitivity to diclazuril.

WARNINGS For use in horses only. Do not use in horses intended for human consumption. Not for human use.

Keep out of reach of children.

PRECAUTIONS The safe use of PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets in horses used for breeding purposes, during pregnancy, or in lactating mares has not been evaluated. The safety of PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets with concomitant therapies in horses has not been evaluated.

ADVERSE REACTIONS There were no adverse effects noted in the field study which could be ascribed to diclazuril.

To report suspected adverse reactions, to obtain a MSDS, or for technical assistance call 1-800-224-5318.

CLINICAL PHARMACOLOGY The effectiveness of diclazuril in inhibiting merozoite production of Sarcocystis neurona and S. 1 falcatula in bovine turbinate cell cultures was studied by Lindsay and Dubey (2000). Diclazuril inhibited merozoite production by more than 80% in cultures of S. neurona or S. falcatula treated with 0.1 ng/mL diclazuril and greater than 95% inhibition of merozoite production (IC 95 ) was observed when infected cultures were treated with 1.0 ng/mL diclazuril. The clinical relevance of the in vitro cell culture data has not been determined.

PHARMACOKINETICS IN THE HORSE The oral bioavailability of diclazuril from the PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets at a 5 mg/kg dose rate is approximately 5%. Related diclazuril concentrations in the cerebrospinal fluid (CSF) range between 1% and 5% of the concentrations observed in the plasma. Nevertheless, based upon equine pilot study data, CSF concentrations are expected to 2 substantially exceed the in vitro IC 95 estimates for merozoite production (Dirikolu et al., 1999) .

Due to its long terminal elimination half-life in horses (approximately 43-65 hours), diclazuril accumulation occurs with once-daily dosing. Corresponding steady state blood levels are achieved by approximately Day 10 of administration.

EFFECTIVENESS Two hundred and fourteen mares, stallions, and geldings of various breeds, ranging in age from 9.6 months to 30 years, were enrolled in a multi-center field study. All horses were confirmed EPM-positive based on the results of clinical examinations and laboratory testing, including CSF Western Blot analyses. Horses were administered PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets at doses of 1, 5, or 10 mg diclazuril/kg body weight as a top-dress on their daily grain ration for 28 days. The horses were then evaluated for clinical changes via a modified Mayhew neurological scale on Day 48 as follows: 0. Normal, neurological deficits not detected.

1. Neurological deficits may be detectable at normal gaits; signs exacerbated with manipulative procedures (e.g., backing, turning in tight circles, walking with head elevation, truncal swaying, etc.).

2. Neurological deficit obvious at normal gaits or posture; signs exacerbated with manipulative procedures.

3. Neurological deficit very prominent at normal gaits: horses give the impression they may fall (but do not) and buckle or fall with manipulative procedures.

4. Neurological deficit is profound at normal gait: horse frequently stumbles or trips and may fall at normal gaits or when manipulative procedures were utilized.

5. Horse is recumbent, unable to rise.

Each horse’s response to treatment was compared to its pre-treatment values. Successful response to treatment was defined as clinical improvement of at least one grade by Day 48 ± conversion of CSF to Western Blot-negative status for S. neurona or achievement of Western Blot-negative CSF status without improvement of 1 ataxia grade.

Forty-two horses were initially evaluated for effectiveness and 214 horses were evaluated for safety. Clinical condition was evaluated by the clinical investigator’s subjective scoring and then corroborated by evaluation of the neurological examination videotapes by a masked panel of three equine veterinarians. Although 42 horses were evaluated for clinical effectiveness, corroboration of clinical effectiveness via videotape evaluation was not possible for one horse due to missing neurologic examination videotapes. Therefore, this horse was not included in the success rate calculation.

Based on the numbers of horses that seroconverted to negative Western Blot status, and the numbers of horses classified as successes by the clinical investigators, 28 of 42 horses (67%) at 1 mg/kg were considered successes. With regard to independent expert masked videotape assessments, 10 of 24 horses (42%) at 1 mg/kg were considered successes. There was no clinical difference in effectiveness among the 1, 5, and 10 mg/kg treatment group results.

Adverse events were reported for two of the 214 horses evaluated for safety. In the first case, a horse was enrolled showing severe neurologic signs. Within 24 hours of dosing, the horse was recumbent, biting, and exhibiting signs of dementia. The horse died, and no cause of death was determined. In the second case, the horse began walking stiffly approximately 13 days after the start of dosing. The referring veterinarian reported that the horse had been fed grass clippings and possibly had laminitis.

ANIMAL SAFETY PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets were administered to 30 horses (15 males and 15 females, ranging from 5 to 9 months of age) in a target animal safety study. Five groups of 6 horses each (3 males and 3 females) received 0, 5 (5X), 15 (15X), 25 (25X) or 50 (50X) mg diclazuril/kg (2.27mg/lb) body weight/day for 42 consecutive days as a top-dress on the grain ration of the horse. The variables measured during the study included: clinical and physical observations, body weights, food and water consumption, hematology, serum chemistry, urinalysis, fecal analysis, necropsy, organ weights, gross and histopathologic examinations. The safety of diclazuril top-dress administered to horses at 1 mg/kg once daily cannot be determined based solely on this study because of the lack of an adequate control group (control horses tested positive for the test drug in plasma and CSF). However, possible findings associated with the drug were limited to elevations in BUN, creatinine, and SDH and less than anticipated weight gain.

Definitive test article-related effects were decreased grain/top-dress consumption in horses in the 50 mg/kg group.

In a second target animal safety study, PROTAZIL® (1.56% diclazuril) Antiprotozoal Pellets were administered to 24 horses (12 males and 12 females, ranging from 2 to 8 years of age). Three groups of 4 horses/sex/group received 0, 1, or 5 mg diclazuril/kg body weight/day for 42 days as a top-dress on the grain ration of the horse. The variables measured during the study included physical examinations, body weights, food and water consumption, hematology, and serum chemistry. There were no test article-related findings seen during the study.

STORAGE INFORMATION Store between 15°C to 30°C (59°F to 86°F).

HOW SUPPLIED PROTAZIL® (1.56 % diclazuril) Antiprotozoal Pellets are supplied in 2-lb (0.9 kg) and 10-lb (4.5 kg) buckets.

REFERENCES 1. Lindsay, D. S., and Dubey, J. P. 2000. Determination of the activity of diclazuril against Sarcocystis neurona and Sarcocystis falcatula in cell cultures. J. Parasitology, 86(1):164–166.

2. Dirikolu, L., Lehner, F., Nattrass, C., Bentz, B. G., Woods, W. E., Carter, W. E., Karpiesiuk, W. G., Jacobs, J., Boyles, J., Harkins, J. D., Granstrom, D. E. and Tobin, T. 1999. Diclazuril in the horse: Its identification and detection and preliminary pharmacokinetics. J. Vet. Pharmacol.

Therap. 22:374–379.

May 2010 Intervet Inc. 56 Livingston Ave, Roseland, New Jersey 07068 © 2010 Intervet Inc. All rights reserved.

08-10 211.x.3.1.0

Within minutes: Bacteria attach to an available surface.

Within 2-4 hours: Strongly attached microcolonies form.

Within 6-12 hours: An initial biofilm has formed that becomes increasingly well organized and tolerant of antiseptics and antibiotics.

Within 2-4 days: The biofilm is mature and highly resistant to host and environmental influences.

Within 24 hours of mechanical disruption: The mature biofilm has reformed. sheen on the surface. In addition to harboring and supporting the bacteria, the biofilms can increase the minimum inhibitory concentration (MIC) of antibiotics for the bacterial population.

“We may be appropriately dosing our patient with the right concentration of the right antibiotic, but the MIC of that drug may increase up to 200-fold in the face of a biofilm,” Dr. Orsini said. “In addition, many biofilms are polymicrobial.”

The treatment plan is relatively straightforward: 1. Physically degrade the biofilm, 2. Prevent or delay reconstitution of the film, and 3. Repeat frequently for as long as needed, “These biofilms are highly resistant to chemical change,” he explained. “Even with povidone iodine, chlorhexidine, acids, bleach, hydrogen peroxide and some of the surfactants that are supposed to enhance the ability to clear bacteria, the films are quite difficult to manage.”

To physically degrade the biofilm, vigorous débridement is indicated. Depending on the wound, veterinarians can drag a gauze sponge or the back of a scalpel blade across the wound. A pulsed lavage system using moderate pressure of 10-15 PSI has shown efficacy, and even low-frequency ultrasonography has been proposed.

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The idea is to remove the film and the bacteria associated with it, and expose the remaining bacteria to the biocide.

To prevent reformation of the biofilm, choose an appropriate antibiotic.

“I always stress the importance of culture as an important first step,” Dr. Orsini said.

“You should have some idea of the bacterial ecology of the particular wound.”

Systemic antibiotics are common, and topical silver sulfadiazine is an excellent biocide for killing the bacteria. Regional perfusion has also shown benefits.

“Regional perfusion after débridement is best in the first 24 hours,” he explained.

“The biofilm reforms in a short time. If the bacteria were originally resistant to antibiotics before removal of the biofilm, they will often revert to the original susceptibility after the film reforms.”

Repeat degradement of the film should be performed daily. After the upper hand has been established, the procedure can be repeated every other day until a healthy wound is observed.

Frequent débridement also decreases the duration of treatment and reduces the overall cost.

“You’re better off front-loading than back-loading,” Dr. Orsini said. “Be aggressive early in débridement, and the time invested by the clinician decreases and the costs for MeV the owner goes down.”

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Orthopedics

5 Tips For the Ultrasound

Stifle Exam

As imaging technology increases in equine practice, it is important to take a step back and make sure your fundamentals are solid.

This will enable practitioners to pinpoint areas of concern, explained Cooper Williams, VMD, DACVSMR, of Equine Veterinary Care of Central Maryland, in Hampstead.

“With the advances in MRI, contrast CT scans, scintigraphy, ultrasonographic techniques and radiographic techniques, do not forget your basics,” he said. “A good basic clinical examination funnels the information down so that you can better get to the area of interest when you’re imaging.”

At the recent meeting of the Northeast Association of Equine Practitioners held in Niagra Falls, NY, Dr. Williams offered five tips to help get the right image.

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Combine Imaging

Most clinics are equipped to obtain radiographs and ultrasonographic images, and these two modalities frequently are enough to diagnose many issues. For stifle examinations, however, Dr. Williams tends to reach for the transducer before the lead-lined vest.

“Most of the structures in the stifle can be imaged on ultrasound, and not by radiography,” he explained. “If you combine the two modalities, then most times you’re going to get to the bottom of what’s going on.”

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Take Several Views

Combining transectional and longitudinal views is essential to a more thorough sonographic examination. It is also important when obtaining each of these views, to fan the probe in a survey fashion.

“You may miss things in both the cross-sectional and longitudinal views if you don’t fan the probe,” Dr. Williams said.

“Don’t just try to get one perfect image.”

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Angle Contrast Imaging

The angle contrast ultrasound technique (ACUST) allows the veterinarian to visualize nonlinear tissue; those that are not in the same orientation as the fibers that are typically seen in a regular or perpendicular view.

Certain structures become much more vivid using the ACUST, but it is not limited to the stifle. This technique can be useful in multiple areas of the body to differentiate between acute and chronic conditions, as scar tissue will show up as more echogenic then

the surrounding tissue.

“When holding the transducer against the limb in a perpendicular view, dip the probe approximately 15° to 20°,” Dr. Williams explained.

“For instance, in the palmar metacarpal region, you can see the fibrocartilage layers of the superficial digital flexor tendon as more echogenic, and the actual tendon fiber is less echogenic. The deep flexor tendon will also be less echogenic and you can see the fine architecture of the tendons.”

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Know Your Anatomy

Shutterstock/Yulia Terentyeva

Anatomic familiarity is necessary, the stifle has14 ligaments and tendons, two menisci and cartilage surfaces in the stifle that are not visible on radiography. Veterinarians should be comfortable with all of these structures, their locations, what they look like in a healthy horse, and what pathology looks like.

“That’s another reason I go for my ultrasound machine first,” he said. “Most of the pathologies are going to be visible on ultrasound.”

Dr. Williams recommended The International Society of Equine Locomotor Pathology’s (ISELP) anatomy review. The review divides the body into eight regions, and each region is covered in separate threeday modules that can be taken over the course of two years.

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Be meticulous

“Be methodical, set a plan and follow it every time,” he explained. “You will miss things if you don’t do it this way. Some people have a brain that can sort it out on the fly, but most people need a methodical plan.”

Dr. Williams noted that his method starts by examining a standing horse medially, cranially, laterally and caudally.

Finally he will place the horse on a flex stand and examine the cranial aspect again in the flexed position.

Orientation Convention Cooper Williams, VMD, DACVSMR, is a big believer in international standards for orientation of images.

“There is a lot of argument in the profession as to how you should orient your image,” he said. “If we are sending images to people, it would be helpful if we all do the same thing.”

Dr. Williams echoed the International Society of Equine Locomotor Pathology (ISELP) imaging convention: • Medial on the left • Proximal on the left • Dorsal on the left • Cranial on the left • Left on the left “If you do it this way, you’ll never have to look at an image and wonder where you are or what part of the structure you are looking at,” he explained.

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news notes

Better understanding of equine grass sickness

Courstesy of The Equine Veterinary Journal

By Marie Rosenthal, MS Despite more than 100 years of research, the cause of equine grass sickness (EGS) remains unknown, but new research points away from Clostridium botulinum.

Researchers identified key differences between EGS and botulism that questions the hypothesis that EGS is caused by C. botulinum neurotoxins. C. botulinum is a common soil bacterium, so the hypothesis was not unreasonable; most cases occur among grazing horses.

The researchers found that EGS causes autonomic and enteric neurodegeneration and increases the expression of certain proteins that botulism does not, suggesting that EGS is unlikely to be caused by botulism neurotoxins. “Given that our recent research suggests that EGS is unlikely to be caused by neurotoxins from Clostridium botulinum, we are now moving on to determine whether EGS is caused by ingestion of mycotoxins produce by pasture fungi,� explained Professor Bruce McGorum, head of the equine section at the Royal

Horse with equine grass sickness

(Dick) School of Veterinary Studies & Roslin Institute in Edinburgh Scotland.

EGS causes gut paralysis as a result of damage to parts of the nervous system that control involuntary functions. The United Kingdom has the highest incidence of EGS in the world, where an estimated 1% to 2% of horses are killed by the disease. Cases are more common in the spring.

In addition to identifying key differences between EGS and botulism, The Equine Veterinary Journal also published three other EGS studies in a free special collection (http://bit.ly/2dC7Drr). Researchers report novel risk factors, a new diagnostic technique and show the value of monitoring weight loss to improve the predictive value of survival.

Another study suggests that the high incidence of the disease in Eastern Scotland might be associated with the particular composition of macro and trace elements in pasture soil.

While most horses with EGS can be diagnosed readily by experienced veterinary surgeons, some cases present a diagnostic challenge. The only way to definitively diagnose the disease in a live horse is to demonstrate the characteristic degeneration of nerves within biopsies of the intestine. Unfortunately, biopsies can only be collected by performing abdominal surgery under general anesthesia.

In a third study, the researchers found the characteristic degeneration of nerves in small biopsies collected from the tongues of horses with EGS during necropsy.

Examining these biopsies, could accurately differentiate control horses from EGS cases, which could someday offer a relatively non-invasive diagnostic method.

About 55% of cases survive, but objective criteria for predicting survival are lacking. The fourth study reported that non-survivors saw more wasting resulting in a greater rate and magnitude of bodyweight loss than survivors. Survival prediction curves were published to allow the use of body weight data to predict whether a horse with chronic EGS was likely to survive.

MeV

For more information: Wylie CE, Shaw DJ, Fordyce FM, et al. Equine grass sickness in Scotland: A case-control study of environmental geochemical risk factors.

McGorum BC, Scholes S, Milne EM, et al. Equine grass sickness, but not botulism, causes autonomic and enteric neurodegeneration and increases soluble N-ethylmaleimide-sensitive factor attachment receptor protein expression within neuronal perikarya. McGorum BC, Pirie RS, D. Shaw D, et al. Neuronal chromatolysis in the subgemmal plexus of gustatory papillae in horses with grass sickness. Jago RC, I. Handel I, Hahn CN, et al. McGorumBodyweight change aids prediction of survival in chronic equine grass sickness.

All published on the Equine Veterinary Journal, available free at http://bit.ly/2dC7Drr 10

Issue 10/2016 | ModernEquineVet.com

Revolutionize Client Communications With New HorseDialog App Zoetis launched a new horse health care and management app to help veterinarians improve patient compliance rates, build client loyalty and communicate more effectively with clients.

HorseDialog can be tailored using the veterinarian’s own practice branding, details and imagery, and marketed to your clients as an innovative, user-friendly and highly efficient way of managing their horse’s health and wellbeing.

HorseDialog is a white label mobile app into which Zoetis will build practice details and branding. Clients, using a unique practice ID code supplied by the veterinarian, can download it from the Apple App Store http://apple.co/2eb5mYe and Google Play Store http://bit.ly/2dIDqaK. It enables users to monitor their horse’s management and preventative care, with direct input from their veterinarian to establish health care schedules, such as vaccinations, medication protocols and rehabilitation programs.

HorseDialog is a highly intuitive app. By following the brief tutorials on each screen your clients can quickly and securely input all the essential data for every horse in their care, including passport number, microchip ID and insurance policy details. This important information is directly accessible to your practice on the HorseDialog web dashboards available on the VetSupport+ Gateway. The VetSupport+ login is connected to Zoetis’ full cloud-based digital solutions, allowing you to toggle between HorseDialog applications for a rich, data-driven experience.

The HorseDialog web dashboards enable: • Remote, electronic engagement with horse owners through the HorseDialog Mobile Community • S egment communication based upon the horses’ health status or condition • Performance tracking to improve medical outcomes • Creation of new health insights with enhanced VetSupport+ analytics • I mprovement of the clinical value vets can produce HorseDialog’s highly organized care schedule allows horse owners to input key details about their

horse’s personal routine. They can add the things they do daily or weekly for their horse, such as feeding, exercise, turnout and medication. They can schedule events that happen every few days, months or annually in their horse’s lifetime such as regular medication, vaccinations, farriery, worming and weight measurement. They can even add past events for multiple horses — such as last date of a fecal worm egg count — to build a thorough history for every horse.

Specific contacts for each horse can be stored, such as the name and number of its farrier, rider or yard manager and push notifications can be set up to make sure your owners don’t miss any appointments or administrations of medication.

“HorseDialog was easy to set up and is easy to use,” said Sarah Godden, equine administrator at Endell Equine Hospital in Salisbury. “It allows us to view full details of day to day care, feeding and exercise routines, as entered by the owner, all useful information that we may not otherwise be privy to. We have also improved compliance by keeping clients up to date with medication reminders.”

MeV To find out more, visit www.zoetis.co.uk.

ModernEquineVet.com | Issue 10/2016

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technician update

Colic in a Young Miniature Horse

By Heather R. Hopkinson, RVT VTS-EVN

Courtesy of Heather Hopkinson, NC State University

A 4-month-old female miniature horse was admitted to the North Carolina State’s Veterinary Teaching Hospital. The filly, which weighed 46.8 kg, presented with a five-day history of colic. She was being weaned and her owners had expected her sale to be completed within one week. Both of her owners were small animal veterinarians and had been treating her symptomatically since the onset of colic.

On the first two days of her arrival, she was given 1 liter of IV lactated Ringers. She had also received DMSO, oral fluids via nasogastric tube, and warm water enemas. Her owners had also been administrating 60 mg of Flunixin every 24 hours for the previous 2 days.

Upon arrival to NCSU-VTH, a physical exam was done, which showed some abnormalities. She had a rectal temperature of 103.7° F and a heart rate of 150 beats per minute (bpm) with normal sinus rhythm.

The mare was tachypnec with a respiratory rate of 90 respirations per minute and lungs auscultated clear bilaterally. She was markedly bloated with normal to decreased borborygmi in all four quadrants. Mucous membranes were pink with a capillary refill time of

Preparing for the standing left flank exploratory laparotomy.

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less than 2 seconds. No ocular or nasal discharge was noted. The mare’s digital pulses were slightly elevated in all four limbs. Her initial blood work also showed some abnormalities. Packed cell volume (PVC) was 46%, plasma protein 7.9 g/dL, fibrinogen 800 mg/dL, creatinine kinase 677 units/L, and lactate was 2 millimoles/L. At this time a nasogastric tube was placed, yet no net reflux was yielded. A 14 gauge 5.25 inch over the needle IV catheter was placed in the mare’s left jugular vein, and secured in place with suture (2-0 Ethilon on a straight needle). The ultrasonography exam revealed that the small intestine appeared mildly distended but was observed to have good motility.

There was severe gas distention noted within the large colon and cecum. The stomach was mildly distended but in its normal location, and there was no free fluid noted in the abdomen. The owners elected to try trocharization. A 16-gauge, 3.25-inch catheter was passed into the cecum (location based on ultrasound), which was approached from the right flank.

A moderate amount of gas was removed from the cecum to decompress her abdomen. Amikacin (0.5 mL) was injected through the catheter as it was removed from the abdomen.

The mare did not show any signs of relief with the trocharization. The owners were given several options including standing surgery, general anesthesia surgery and euthanasia. All the risks were discussed and because of the cost, they decided on the standing left flank exploratory laparotomy.

The mare was sedated with 10 mg of detomidine and 10 mg of butorphanol. She was placed on a table to enable the surgeon to have better access to the surgical site. IV fluids were administrated throughout the surgical procedure. A Cardell monitor was used to monitor heart rate and rhythm, respirations, blood pressure and oxygen levels. In addition to the Cardell we used stethoscopes and our eyes to make sure this mare was doing well under these circumstances. The incision site was anesthetized with 15 mLs of Carbocaine. An approximately 10 cm vertical incision was made over the left flank through the skin and

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 10/2016

*American Association of Equine Veterinary Technicians and Assistants

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Courtesy of Heather Hopkinson, NC State University

technician update

The material was carefully massaged aborally and eventually out of the anus.

subcutaneous tissues. At this time, the mare was really sedate, and we no longer could keep her standing so we placed her in right lateral recumbancy. External and internal abdominal oblique and transverse abdominal muscles were bluntly dissected with Mayo scissors and the peritoneum was bluntly incised with Metzenbaum scissors and digital manipulation. The abdomen was explored and on several occasions, gas in the large colon and the cecum was decompressed by suction using a 20-gauge, 1.5-inch needle. An approximately 5 cm firmly impacted fecalith was located in the small colon and this portion of the bowel was exteriorized. The serosa surrounding the fecal ball was hyperemic and inflamed oral to the obstruction for a distance of about 8 cm.

Twenty-milliliter boluses of sterile saline were injected into the small colon surrounding and directly into the fecalith to manually break down the obstruction. The fecalith was reduced intralumenally; this material was carefully massaged aborally and eventually out of the anus. A stallion catheter was inserted into the anus and boluses of 60 mL saline were flushed into the rectum to aid in the removal of all fecal material. Copious amounts of carboxymethylcellulose were applied over the bowel throughout the procedure to prevent adhesion formation. After all the fecal material was removed, the remainder of the abdomen was briefly explored. The flank incision was closed starting with the transverse abdominal mus14

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cles and peritoneum, using No. 1 polusorb suture in an interrupted cruciate pattern. The internal abdominal oblique muscle was closed in the same manner.

The external abdominal oblique and subcutaneous tissues were closed with 2-0 vicryl in a simple interrupted pattern, while the skin was apposed with 2-0 monocryl using a continuous horizontal mattress pattern. An adhesive bandage was applied over the incision and secured with multiple skin staples. The mare recovered without incident.

After recovery, the mare was lead to her stall and placed on IV fluids (Lactated Ringers) at a rate of 500 mL an hour. She was also placed on the following medications: IV flunixin 25 mg, IV gentamicin 300 mg, IV penicillin 1 million units and oral ranitidine 300 mg.

The next day, the mare seemed a little uncomfortable standing with her head held low in the corner of her stall. However her physical examination was within normal limits with her rectal temperature being 100.5° F, heart rate of 64 bpm, 24 rpm, mucous membranes were pink and capillary refill time of less than 2 seconds, digital pulses were within normal limits in all four limbs. She had seven bowel movements since surgery all of which were diarrhea. After her physical examination and morning feeding, the mare seemed brighter. Her bandage was still in place on the left flank.

All medications were continued throughout the day. IV fluids were to be discontinued that day. In addition to offering bran mashes throughout the day the mare was

allowed to graze every 2 hours for 1 to 2 minutes at a time. She seemed very bright for hand grazing and ate with a voracious appetite.

Two days after surgery, the mare seemed very bright and comfortable ambulating very well around her stall. Her physical examination was within normal limits with her rectal temperature being 100.4° F, heart rate of 68 bpm, 28 rpm, mucous membranes were pink with a capillary refill time of less than 2 seconds, digital pulses were within normal limits in all four limbs. She had four bowel movements overnight, some diarrhea and some normal. She continued to have a great appetite for grass and was recovering from surgery as well as could be expected.

All IV antibiotics were discontinued, and the mare was switched to oral antibiotics (trimethoprimsulfamethoxazole 1,440 mg). Her IV catheter was removed and antibiotic ointment was applied to the catheter site. Both jugular veins appeared normal.

The mare’s abdominal bandage was changed to see how the incision was healing, which was doing well, and an abdominal bandage was replaced. Because the owners were small animal veterinarians, they felt comfortable managing the mare postoperatively at home. Therefore, she was released when she seemed healthy enough for travel.

The mare was discharged with the following instructions. Medications to be administered include: IV Flunixin 25 mg given every 12 hours for the next 4 days then as needed for pain, Ranitidine 300 mg given by mouth every 8 hours for the next 10 days, TMP-SMX 1,440 mg given by mouth every 12 hours for the next 4 days. Her abdominal bandage was to stay in place for the next three days as long as it remained clean and dry. If it had to be removed because it became wet or dirty, it did not have to be replaced. The mare should be kept on stall rest for the

next three weeks with controlled grazing only. After the three weeks she could be turned out in a small paddock for another five weeks before she could return to her normal pasture turnout.

This case required many nursing skills. For all cases admitted to the NCSU-VTH, baseline vital signs and a history is obtained. Beyond those basics each case is treated individually and is dependent on clinician discretion. All patients that are admitted to the NCSUVTH receive a physical examination and are assigned a pain score at least twice a day. This case shows that all colics that are presented to the NCSU-VTH are worked up summarily but the outcomes can be different.

I was present when this patient was admitted to the NCSU-VTH and the advanced skills I performed were essential. I placed the nasogastric tube and attempted to obtain reflux, restrained for IV catheter placement, assisted in surgery with maintaining a sterile field and using good antiseptic technique when passing instruments, monitored patient under sedation during surgical procedure, and helped recover the patient after the surgical procedure was finished. The most important skill I used during this case was my monitoring skills.

Despite machine monitoring, it is essential to always have a stethoscope at hand and to closely observe heart rate, respirations rate, temperature and mucous membranes.

MeV

About the author

Heather, who is an equine veterinary technician at the North Carolina State University College of Veterinary Medicine, received her VTS in Equine Veterinary Nursing in 2011 and is the current president of the Academy of Equine Veterinary Nursing Technicians. She is also the current vice president of the North Carolina Association of Veterinary Technicians.

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ModernEquineVet.com | Issue 10/2016

15

Infectious diseases

Screwworm Found For First Time in 30 Years The New World screwworm

fly has been detected in Florida for the first time in 30 years, according to the Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS). The screwworm was found in deer from a wildlife refuge in Big Pine Key. In response to this infestation, Florida Commissioner of Agriculture Adam H. Putnam declared an agricultural state of emergency in Monroe County. “The screwworm is a potentially devastating animal disease that sends shivers down every rancher's spine. It's been more than five decades since the screwworm last infested Florida, and I've grown up hearing the horror stories from the last occurrence,� said Mr. Putnam.

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New World Screwworms are fly larvae that can infest livestock and other warmblooded animals, including humans.

In addition to the samples from three Key deer that were confirmed positive for screwworm, there are other Key deer from the same refuge and a few

pets in the local area that exhibited signs of screwworm over the past two months, although no larvae were collected and tested in those cases. All of the potentially affected animals are from the same area of Big Pine Key and No Name Key. There have been no human or livestock cases.

Animal health and wildlife officials at the state and federal levels are working jointly to address these findings. Response efforts will include fly trapping to determine the extent of the infestation, release of sterile flies to eliminate the screwworm fly population, and disease surveillance to look for additional cases in animals.

The initial goal will be to keep the infestation from spreading to new areas while eradicating the New

news notes

screwworm using a form of biological control, called the sterile insect technique, which releases infertile male flies in infested areas. When they mate with local females, no offspring result. With fewer fertile mates available in each succeeding generation, the fly, in essence, breeds itself out of existence.

USDA used this technique to eradicate screwworm from the U.S. and worked with other countries in Central America and the Caribbean to eradicate it there as well. Today, USDA and its partners maintain a permanent sterile fly barrier at the Darien Gap between Panama and Colombia to prevent the establishment of any screwworm flies that enter from South America.

Experts with the University of Florida Institute of Food and Agricultural Sciences and College of Veterinary Medicine are assisting in eradication efforts. Parasitologist Heather Walden, PhD, a member of the college’s faculty, was involved in confirming the identification of specimens collected from infected deer. Jack Payne, UF senior vice president for agriculture and natural resources, noted that the outbreak appears to be limited to a small area but affirmed that strong, immediate action is needed to manage the outbreak and resolve the situation.

“This foreign animal disease poses a grave threat to wildlife, livestock and domestic pets in Florida. Though rare, it can even infect humans. We've eradicated this from Florida before, and we'll do it again. We will work with our partners on the federal, state and local level to protect our residents, animals and wildlife by eliminating the screwworm from Florida.

The public's assistance is crucial to the success of this eradication program,” said Mr. Putnam. MeV

Equioxx Tablets Now Available The new tablet formulation of firocoxib (Equioxx, Merial), which was approved in July, is now available.

The new 57 mg chewable tablet formulation of the only equine coxib non-steroidal anti-inflammatory drug (NSAID) is only available through a veterinary channel. Owners must receive a prescription for the product.

Firocoxib is now available in three formulations– injection, paste and tablet. It is a once-daily treatment to control pain and inflammation associated with equine osteoarthritis, also called degenerative joint disease. All three firocoxib formulations allow for consistent therapy with the same active ingredient. It has a proven safety profile and spares COX-1 inhibition while inhibiting COX-2 prostaglandin production.

“EQUIOXX Tablets are chewable and easy to administer to horses, with or without feed,” said Hoyt Cheramie, DVM, MS, senior manager, Merial Large Animal Veterinary Services. “For veterinarians prescribing an NSAID, the tablet is one of three safe and effective options in the family of Equioxx formulations.”

Dr. Cheramie said horse owners, trainers and veterinarians attending horse shows and other events should ensure they are in compliance with medication rules for each association before using any formulation of firocoxib.

Veterinarians should advise horse owners to watch 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 less than 1 year of age or in breeding horses, or pregnant or lactating mares.

For more information, visit www.equioxx.com. MeV

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Shutterstock/ Rita Kochmarjova

World screwworm flies from the affected Keys.

The state has established an Animal Health Check Zone from mile marker 91 south. Animals traveling north will be given health checks at an interdiction station located at mile marker 106 to ensure that they do not have screwworm. This checkpoint will ensure that the screwworm does not travel north and infest other areas of Florida.

Residents who have warmblooded animals should watch their animals carefully and report any potential cases to 1-800-HELPFLA (1-800-435-7352) or nonFlorida residents should call (850) 410-3800. Visitors to the area should ensure any pets that are with them are also checked to prevent the spread of this infestation.

While human cases of New World screwworm are rare, they have occurred.

Cochliomiya hominivorax, the New World screwworm fly, is a significant pest of domestic animals, wildlife and even people in areas where the insect is well-established.

It has not been widely present in the U.S. since the 1960s but is still found in most of South America and in five Caribbean countries.

New World screwworms are fly larvae that can infest livestock and other warm-blooded animals, including people. They most often enter an animal through an open wound and feed on the animal's living flesh. While they can fly much farther under ideal conditions, adult flies generally do not travel more than a couple of miles if there are suitable host animals in the area. New World screwworm is more likely to spread long distances when infested animals move to new areas and carry the pest there.

In the 1950s, USDA developed a new method to help eradicate

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