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The Modern

Equine Veterinarian July 2012

Vol1 No2

Changing paradigm How to fight parasite resistance

Inventory is money! Best insemination technique? Biopsy accurate in endometriosis evaluation 1

July 2012 | TheModernEquineVeterinarian.com


Table of Contents

Cover story

4 Saving a precious resource Three experts tell you how to develop an individualized program and explain why you should

Reproductive medicine

Comparing insemination techniques: Which is best?.................. 8 New study compares hysteroscopic and transrectally guided deephorn insemination with low sperm count samples

Biopsy accurate for evaluating endometriosis.............................12 Current grading system for biopsy coincides with the results from a whole-wall sample.

Technician Update

Inventory is money!................................................................................16 Effective inventory management means more than just ordering new supplies

Emerging diseases

Lawsonia intracellularis: species specific.............................18 Stop blaming pigs when foals come down with EPE

The Feedbag:

21 Fatter than they look newsnotes

15 Motion detectors locate lameness sooner 20 Rescue partnership gives horses a second chance LEGAL DISCLAIMER: The content in the digital content is for general informational purposes only. PercyBo Publishing 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 reserves the right to alter or correct any content without any obligations. Further, 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 Publishing. The content is for veterinary professionals. ALL RIGHTS RESERVED. Reproduction in whole or in part without permission is prohibited.

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TheModernEquineVeterinarian.com | July 2012

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cover story

Saving a

precious resource B

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Today’s parasite control requires an individualized program that involves testing, selective deworming and environmental controls. 4

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Since many anthelmintic drug

classes have developed resistance, veterinarians should be in the forefront of designing individualized parasite control programs to preserve this precious resource. The threat of resistance should change parasite control strategies from routine prophylactic deworming of the entire herd to more individualized programs.

New strategies require surveillance and testing, selective deworming and environmental controls. Clients may resist this advice because it could increase the cost of deworming, at least initially. Tell them they should see a savings later because they will deworm their horses less often. Changing the practice paradigm just might delay the emergence of parasites that are totally resistant to available anthelmintic drugs. “Most common equine parasites are resistant to at least one class of dewormer,” said Craig R. Reinemeyer, DVM, PhD, president of East Tennessee Clinical Research in Rockwood, Tenn. “And it has to do with how intensely various products have been used. We need to deworm less, and we need to deworm more intelligently.” The equine industry desperately needs new anthelmintics because no novel agents have been introduced in the United States since the introduction of ivermectin in 1981. Monepantel has been approved in other countries but is not available in the United States. Anthelmintic resistance is not just a U.S. issue; it is a worldwide phenomenon, according to Ray M. Kaplan, DVM, PhD, DEVPC, professor of parasitology at the University of Georgia College of Veterinary Medicine in Athens, who wrote a report on the problem last year in TheModernEquineVeterinarian.com | July 2012

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cover story Veterinary Parasitology. “Over the past 10 to 15 years, we have witnessed a rapid increase in both the prevalence and magnitude of anthelmintic resistance, and this increase appears to be a worldwide phenomenon,” he wrote.

Surveillance

Mary G. Rossano, PhD, assistant professor, equine epidemiology and parasitology at the University of Kentucky College of Agriculture, suggested that owners stop looking at the calendar when deciding when to deworm and instead use an evidenced-based approach to develop a deworming schedule. “Get fecal egg count test re-

“Remember the 20-80 rule — about 20% of the horses have about 80% of the parasites.” Regardless of herd size, try to test at least 5 or 6 individual horses, Reinemeyer suggested. For very large herds, test about 10% of the horses, or 6 animals, whichever number is larger. In either case, remember to test the same horses before and after treatment to compare the results, he added. Treatment frequency can be based on results if it has been at least 4 months since the most recent deworming. Horses that are low or moderate shedders (<200 eggs/g to 500 eggs/g) only need deworming once or twice a year. High shedders (>500 eggs/g) should be dewormed more often. Treat the high shedders

away with much less frequent deworming in horses that are shedding relatively few eggs. So, if you test a large group of adult horses, you might find that only 10% to 20% of the horses are shedding enough eggs to be worth treating,” Rossano said. “By doing that, we are lessening the selection pressure that causes resistance in parasites.” Small strongyles are not normally a health concern, so low and medium shedders could be treated once or twice a year to help control large strongyles, bots and tapeworms. “All horses probably could use two treatments a year at 6-month intervals. I use what I call the equinox schedule — autumn and spring. If one uses a product that is larvicidal for large strongyles at least once every 6 months, it should eradi-

Photos courtesey of Dr. Ray Kaplan

Horses that shed <200 eggs/g to 500 eggs/g only need deworming once or twice a year. High shedders (>500 eggs/g) should be dewormed more often.

sults and follow up to see how effective the drugs are on the parasites,” she said. Each of the common drug classes must be evaluated for efficacy. The first step is to find out which anthelmintic treatments are effective within the herd and how long they suppress egg production. Fecal egg count reduction testing (FECRT) will also provide an idea of the worm burden on the farm and among the horses. A small percentage of any given herd will harbor most of the parasites, explained Kaplan. 6

July 2012 | TheModernEquineVeterinarian.com

and then do another fecal egg count in 2 weeks to see if the product is effective. If the egg counts do not go down by at least 90%, the product is resistant on that farm, and the veterinarian should advise the owner to switch products. [{(pre – post) / pre} × 100 = % efficacy.] If the egg counts go down, wait a bit and test again to determine the “egg reappearance period,” which is the time it takes for egg counts to rise. Once they do, the high shedders may need to be retreated, depending on the time of year. “Emerging research is now demonstrating that we can get

cate these dangerous worms from your herd,” Reinemeyer said. In addition, there is no need to deworm if there is no threat. This means that even high shedders should only be treated certain times of the year, depending on the weather. “In a very cold climate, moderate temperature climate or the deep south, the timing of deworming will be different,” said Kaplan. “We want to time treatments to coincide with transmission of the parasites to get the most benefit.” Horses in cold climates generally benefit most if treatments are concentrated between spring and autumn,


Photos courtesey of Dr. Ray Kaplan

whereas autumn to spring timing is more appropriate for those in warm climates. Rotational deworming in which drug classes are alternated with each treatment does not work, he added. “It makes no sense to rotate from a drug that works to a drug that doesn’t work,” Kaplan explained. “You want to use drugs that are effective at appropriate times of year to kill the various species of parasites that need to be killed.” Veterinarians must have buyin from owners, so they should explain why horses that are dewormed less often are not at risk for disease. Horses have evolved with parasites, and small worm burdens will not hurt them, according to Reinemeyer. “If you feed a decent diet and maintain a reasonable stocking rate, you’re not going to have horses dropping dead from parasites,” Reinemeyer said. “If you have parasitic disease in a population of horses, you don’t have a worm problem, you have a management problem. Either you have too many horses on too few acres, their diet is poor quality or they are experiencing excessive stress.” The biggest problem in the fight against resistance is the lack of long-term data and lack of good diagnostic tools to determine long-term consequences of selective therapy programs, according to Martin Krarup Nielsen, DVM, PhD, an assistant professor in the department of large animal sciences at the University of Copenhagen in Denmark. “There is general agreement that the traditional treat-all at frequent interval approach should be abandoned, and that optimal parasite control can be maintained with far fewer anthelmintic treatments. But better diagnostic techniques and more evidence documenting the long-term consequences of selective therapy

Parascaris equorum, an ascarid, is a rigid, heavy-bodied roundworm that can grow to 50 cm long.

programs are needed to develop and validate systems for sustainable equine parasite control,” he wrote in Veterinary Parasitology.

Environmental controls

Horses have instinctively found a way to reduce their worm burden. If they have enough room, horses will segregate their pasture into lawns and roughs. So, do not overstock horses. “There is a huge difference in the amount of manure in different areas of a pasture. If the horse has enough pasture, he will avoid grazing where he defecates. If they are overstocked and there is not enough pasture, he will be forced to graze closer to the manure and will acquire more parasites,” said Kaplan. “Pasture management is an important piece of the parasite control puzzle.” Pick up manure and place it in

an active compost pile because the heat that comes from composting is lethal to strongyle larvae and ascarid eggs. By the time the compost is ready to be applied to pastures or gardens, the parasites are dead. “If you are doing selective deworming that targets the high shedders, cleaning up the manure and composting it, you can bring down the larval contamination of your pasture very effectively,” Rossano said. MeV

For more information:

Reinemeyer CR. Anthelmintic resistance in non-strongylid parasites of horses. Vet Parasitol 185(1):9-15, 2012. Rossano MG. Shortened strongyle-type egg reappearance periods in naturally infected horses treated with moxidectin and failure of a larvicidal dose of fenbendazole to reduce fecal egg counts. Vet Parasitol 173:349352, 2010. TheModernEquineVeterinarian.com | July 2012

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REPRODUCTIVE MEDICINE

Comparing insemination

which is

Photos copyright Š Dr. Shelby Haden

Transrectally Guided Technique

Dr. Shelby Hayden carries the 75-cm flexible, intrauterine insemination pipette and 80-cm flexible inner catheter (re-inserted) into the vagina, followed by passage of the pipette through the cervix.

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Hysteroscopic (HYS) and transrectally guided (TRG) deep-horn insemination both resulted in similar pregnancy rates, even when very low sperm numbers were used to inseminate the mares, according to a recent study that compared the two techniques. Deep-horn insemination, which involves placing semen at the tip 8

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Dr. Shelby Hayden examines the inner catheter for semen following insemination insemination procedure. She is assisted by technician Katrina LaCaze.

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of the uterine horn on the same side as the ovary containing the preovulatory follicle, requires less sperm to impregnate a mare than traditional uterine body insemination. Multiple studies have compared pregnancy rates following HYS or TRG deep-horn insemination, but they have had conflicting results,

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according to Shelby Hayden, DVM, DACT, clinical assistant professor, theriogenology at Oklahoma State University Center for Veterinary Health Sciences. Two studies, one done in Colorado and one in Texas, compared pregnancy rates obtained with HYS and TRG using 5 million motile, fresh sperm and 5 million


techniques:

best?

75-cm flexible, intrauterine insemination pipette and 80-cm flexible inner catheter (removed) by Minitube of America, Inc.

during the transrectally guided deep-horn

Insertion of air through the 75-cm flexible, intrauterine insemination pipette following removal of the inner catheter to remove semen that may have flowed back into the pipette, especially important if the seal between the inner catheter and outer pipette is not adequate.

total, chilled sperm. The Colorado researchers found that the pregnancy rates were significantly higher using the HYS technique, whereas, the Texas researchers found no difference in pregnancy rates between the HYS and TRG techniques. Twelve mares became pregnant with HYS and 10 became pregnant with TRG. “It is important to note that the transrectally guided tech-

niques and equipment utilized in these two studies were different,” Hayden said. “When Colorado workers performed a follow-up study utilizing the same transrectally guided technique utilized by Texas workers, no difference in pregnancy rates between the hysteroscopic and transrectally guided techniques when 20 million sexsorted sperm was inseminated. Yet, it has been suggested by Squires

that the hysteroscopic technique may be the preferred method of deep-horn insemination when fewer than 25 to 50 × 106 sperm are used, especially if the semen is frozen-thawed or sex-sorted.” Because previous studies (most importantly the two studies mentioned above) did not determine and use insemination doses known to result in subfertile pregnancy rates for the stallions in each study, TheModernEquineVeterinarian.com | July 2012

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REPRODUCTIVE MEDICINE excessive numbers of sperm could have been inseminated, compensating for an inferior technique. Pregnancy can still occur when a subthreshold dose is inseminated, especially when it is immediately below the threshold. However, subthreshold doses result in lower than ideal fertility rates, she explained. “We wanted to conduct a study comparing the pregnancy rates following hysteroscopic deep-horn insemination and the transrectally guided deep-horn insemination technique utilized by Texas workers combined with ventrally orienting the tip of uterine horn be-

IM injection of cloprostenal given on day 10 of treatment. Deslorelin was given IM once a preovulatory follicle and prominent uterine edema were detected. Semen was collected from one highly fertile Quarter Horse. Sperm concentration and motility were determined, and the semen was diluted to either 5 × 106 sperm/ ml or 1 × 106 sperm/ml for the insemination dose of 1 × 106 total sperm or 0.5 × 106 total sperm, respectively. Nine of the mares were eliminated from the study because of complications or failure to ovulate.

ferent in pregnancy rates when mares were inseminated with 1 × 106 sperm or 0.5 × 106 sperm. Pregnancy rates also did not differ when the insemination doses of 0.5 or 1 million sperm were combined. Pregnancy rates were higher in mares inseminated with 1 x 106 than in mares inseminated with 0.5 x 106 sperm. “From these findings, we concluded that high fertility can be achieved with very low sperm numbers, but there is a functional threshold below which fertility cannot be improved through these techniques alone,” the researchers

Photos copyright © Dr. Shelby Haden

Hysteroscopic Technique

Dr. Shelby Hayden passes the 1-meter flexible video-endoscope into the uterus in a manner similar to the transrectally guided method. She is assisted by fellow researcher, Dr. Steven P. Brinsko.

ing inseminated that would finally answer the question as to whether one of these techniques would result in superior pregnancy rates,” Hayden said. The researchers tried to impregnate 37 mares ranging in age from 4 to 19 years old, whose ovulation was synchronized by daily intramuscular administration of progesterone and estradiol and a single 10

July 2012 | TheModernEquineVeterinarian.com

Twenty-eight mares were inseminated using both techniques. All 28 mares bred with 1 × 106 and 26/28 mares bred with 0.5 × 106 sperm ovulated with 24 hours of insemination. The remaining two mares bred with 0.5 × 106 sperm ovulated within 48 hours of insemination. Both were bred by HYS and neither was pregnant. There was no significant dif-

wrote in the study, which appeared in Theriogenology. “The key factor to achieving optimal pregnancy rates with either deep-horn technique was to pool the semen on or very close to the oviductal papilla without immediate backflow of the semen down in the uterine bifurcation/ body region,” Hayden said. The inseminator’s skill is im-


portant with both techniques, she added. “With the transrectally guided technique, the inseminator must be a competent transrectal palpator and he/she must possess a moderate to high level of comfort and expertise manipulating the uterus and pipette per rectum. The hysteroscopic technique requires a reasonable level of expertise with the endoscope. So, for some veterinarians a transrectally guided technique will be easier while the opposite will be true for other veterinarians.” When performing the transrectally guided deep-horn in-

do not under any circumstances try to reposition it ventrally,” she said. Sperm adheres to any piece of equipment that it contacts. Minimize the surface area that the semen contacts in your insemination equipment to maximize the percentage of sperm actually deposited into the uterus. These can be accomplished by using one of the following methods: • When breeding with frozen semen, use a flexible pipette that has a stylet designed to allow consecutive insemination of 0.5 ml straws without having to move the pipette

semen, place semen directly into the syringe from the straws, especially when the insemination volume is greater than the volume that the inner catheter of the insemination pipette can hold.

Intrafallopian insemination catheter (Cook Veterinary Products, Spencer, IN, USA)

From left: Drs. Terry L. Blanchard, Steven P. Brinsko and Shelby Haden, who co-authored the paper, prepare to place the 1-meter flexible video-endoscope into the uterine horn ipsilateral to the dominant follicle using transrectal manipulation; transrectal compression of the distal end of the uterine horn ipsilateral to the dominant follicle followed by insufflation of the proximal end of the uterine horn ipsilateral to the dominant follicle; advancement of the endoscope to the tip of the horn ipsilateral to the dominant follicle.

From left: Drs. Terry L. Blanchard, Steven P. Brinsko and Shelby Haden place the semen directly on the oviductal papilla.

semination technique, Hayden recommended holding the uterine tip in a ventral orientation during insemination and for a short time afterward. “I try to hold the uterine horn tip in a ventral orientation for at least 3 minutes. If you lose the ability to hold the tip of the uterine horn in a ventral orientation at any time during or following semen deposition,

from its deep-horn location, when inseminating fresh, frozen, or chilled semen with volumes less than the maximum capacity of the inner catheter, aspirate the semen directly from its container into the inner catheter of the pipette (as shown in the pictures supplied), or • When breeding with frozen

“The transrectally guided technique may be the method of choice because it requires less time for setup and cleanup, and utilizes less expensive equipment,” said Hayden. Deep-horn insemination may not improve pregnancy rates if the semen quality is poor, she reminded. MeV

TheModernEquineVeterinarian.com | July 2012

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REPRODUCTIVE MEDICINE

Biopsy accurate in

endometriosis evaluation

Current grading system for biopsy coincides with results from whole-wall sample. B y

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Veterinarians can feel comfortable

when depending on uterine biopsy to evaluate and grade endometriosis and the fertility of the mare with the disease, according to a recent study published in the Journal of Veterinary Science. “Results from this study confirmed that biopsy can be an indispensable clinical diagnostic tool for evaluating the fertility of mares,” the researchers wrote in the paper Equine endometriosis, or chronic endometrial degeneration, which is associated with decreased fertility, early embryonic death and abortion, is common among older mares. Many factors may contribute to the problem, including age, repeated pregnancies, parturition, chronic inflammation and endocrine problems. The disease is progressive and involves endometrial changes, such as periglandular and stromal fibrosis, chronic inflammation and atrophy. However, until now, no study had evaluated the role that inflammation and extracellular matrix (ECM) remodeling might play in endometriosis. In addition, recent studies have ques-

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tioned the validity of biopsy to assess the grade of the disease, according to lead researcher Luca Aresu, DVM, PhD, assistant professor in Padua School of Veterinary Medicine in the department of comparative biomedicine and food science in Italy. “Despite the widespread use of this technique [biopsy], recent studies have questioned the efficacy of such methods due to the low reliability of a single endometrial biopsy to accurately assess the grade of endometriosis,” the researchers wrote.

Study goals

In the study, researchers looked at histomorphologic lesions in 35 endometrial samples. They took the samples from various breeds, whose reproductive histories were unknown to them at the time. (Twenty-five of the mares were in oestrus and 10 were in diestrus.) The researchers tested both uterine biopsies and uterine-wall samples and compared the results. Seventeen samples were stained with antibodies against MMP-2, MMP-9,


Courtesy of Dr. Aresu Luca

Histopathology of the equine endometrial specimens.

A1 and 2: grade I, B1 and 2: grade IIA, C1 and 2: grade IIB, D1 and 2: grade III. Specimens were classified according to Kenney and Doig classification of endometriosis. Hematoxylin and eosin stain (A1, B1, C1, and D1) and Massonâ&#x20AC;&#x2122;s trichrome stain (A2, B2, C2, and D2), Ă&#x2014;40 [J Vet Sci (2012), 13 (2), 171-177]. TheModernEquineVeterinarian.com | July 2012

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REPRODUCTIVE MEDICINE portant for many physiologic and pathologic processes, including development of embryos, tissue remodeling, angiogenesis, wound healing and metastasis. In horses, the role of MMPs is still being explored, but it is believed that they play a role in various pathologic processes, including laminitis, arthritis and other degenerative diseases, as well as cancer.

Results

For practicing veterinarians, the most significant finding of this study is that the current grading systems for biopsies coincided the results from a whole-wall sample. As was expected, younger mares tended to have lower endometriosis grades than older mares. In addition, the researchers found that the number of fibrotic nests and fibrosis grade were the best predictive factors when veterinarians evaluate fertility. Inflammation, however, correlated poorly with endometriosis grade. Aresu said this could be due to the biopsy site, grade of endometriosis, correlation between the amount of fibrotic tissue and the number of inflamma-

As was expected, younger mares tended to have lower endometriosis grades than older mares. In addition, the researchers found that the number of fibrotic nests and fibrosis grade were the best predictive factors when veterinarians evaluate fertility. 14

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tory cells or the mare’s cycle. “Endometrial degeneration and fibrosis are known to originate from repetitive inflammatory injuries,” the researchers wrote. “Damage from chronic inflammation triggers a complex tissue reaction resulting in ECM deposition and accumulation within the interstitium. Fibrosis continues to progress even after the inflammatory process has ended. Therefore, progression of the fibrotic process after a critical point becomes independent of inflammation despite the presence of inflammation preceding fibrosis that affects the pathogenesis of endometriosis. This explains the low correlation between inflammation and endometriosis grade observed in the present study.” The results of MMP and TIMP2 (tissue inhibitors of metalloproteinases) testing were inconclusive, and the researchers indicated that further studies are needed to understand more fully the role of metalloproteinases in the pathogenesis of endometriosis. “Veterinarians should keep doing biopsy [to evaluate endometriosis],” Aresu said. “Mucosal biopsy, rather than whole-wall sample, should be sufficient for a diagnosis.” MeV

Frank Fennema/ShutterStock

MMP-14 and TIMP-2. Matrix metalloproteinases (MMPs) are calcium and zinc-dependent proteases thought to be responsible for the degradation and removal of extracellular matrix remodeling, according to the paper. The goals of the study were fourfold: 1. To evaluate the reliability of biopsy samples with entire uterine wall samples for diagnosing and grading. 2. To examine the relationship between the degree of endometriosis and the mare’s age. 3. To look at the role of inflammation in the disease. 4. To look at the expression of different MMPs in the equine endometrium. “The research was organized in two steps,” Aresu said. “The first was to analyze quantitatively the role of inflammatory cells and fibrosis in equine endometriosis, based on the different grades of Kenney classification. In the second step, we concentrated on the MMPs and their distribution in different specimens.” Researchers of human disease have found that MMPs are im-


orthopedics

Motion detectors locate lameness sooner Lameness treatment is more effective if the problem is found early. A professor of equine surgery has developed a technique that enables veterinarians to quickly determine where lameness is occurring. “If veterinarians can detect lameness earlier, before it gets too bad, it makes treatment much easier,” said Kevin Keegan, DVM, a professor of equine surgery at the University of Missouri College of Veterinary Medicine. “Lameness often goes undetected or undiagnosed entirely, which can cause owners to retire horses earlier than needed, simply be-

The Lameness Locator places small sensors on the horse’s head, right front limb and croup, near the tail. The sensors monitor and record the horse’s torso movement while the horse is trotting.

cause they cannot figure out why the horses are unhealthy. The Lameness Locator should be able to help with that as well.” Keegan developed a motion detection system to detect lameness earlier than most veterinarians can using the traditional methods for diagnosis. The Lameness Locator places small sensors on the horse’s head, right front limb and croup, near the tail. The sensors monitor and record the horse’s torso movement while the horse is trotting. The recorded information is then transferred to a computer or mobile device and compared against databases recorded from the movement of healthy horses and other lame horses. The computer then diagnoses whether the horse is lame. The device costs around $15,000 depending on the configuration. Contact Equinosis for more information. http://equinosis.com In a new study published in the Equine Veterinary Journal, Keegan and his colleagues put special adjustable shoes on horses that temporarily induced signs of lameness. The horses were monitored by the Lameness Locator, as well as by a number of veterinarians using any lameness testing methods they wished.

If no lameness was detected by either the veterinarians or the Lameness Locator, the special shoes were adjusted slightly to increase the signs of lameness. This process was repeated until both the Lameness Locator and the participating veterinarians properly identified in which leg of the horse the lameness was occurring. Keegan and McCracken found that the Lameness Locator correctly identified lameness earlier than veterinarians using subjective eye test methods more than 58% of the time and more than 67% of the time when the lameness occurred in the hind legs of the horse. Keegan attributed this to the sensor’s high sensitivity levels. “There are two reasons why the Lameness Locator is better than the naked eye,” Keegan said. “It samples motion at a higher frequency beyond the capability of the human eye, and it removes the bias that frequently accompanies human subjective evaluation.” Because equine lameness may begin subtly and can range from a simple mild problem affecting a single limb to a more complicated one affecting multiple limbs, early detection is the key to successful outcomes. MeV

TheModernEquineVeterinarian.com | July 2012

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Technician Update

Inventory is

money Managing inventory effectively means more than just ordering new supplies

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An inventory manager is more than someone who orders supplies because inventory is money. Unfortunately, equine clinicians do not always think about inventory that way. “The next time you go into your inventory room, just picture that inventory as dollar bills,” suggested Deborah B. Reeder, BA, RVT, VTS (EVN), executive director of the American Association of Equine Veterinary Technicians and Assistants. “Take a picture of

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a big room full of dollar bills and post that on the door. Inventory is the second largest expense in the veterinary practice, after the cost of labor, taking up to 20% of gross revenue. Lost profits from ineffective inventory management will affect all areas of the practice. What really makes inventory management a challenge in many clinics is that inventory managers do not always have the authority to manage inventory properly, Reed-

er said during a presentation at the Western Veterinary Conference. Anyone can order supplies and stock a shelf, but an inventory manager is someone who • can reconcile those orders, •m  ake sure that older drugs are used before their expiration date, • p roperly dispose of those that aren’t, • c onsult with distributors to find the best pricing and • r estrict access to certain products. Practices face three primary challenges in handling inventory: • a bsence of a designated inventory manager •m  ultiple locations for drugs and supplies, and • u nrestricted access to drugs and supplies. “Often there is no designated inventory manager with authority,” said Reeder, “and that is an important part. The clinic can


Tactics to Control Inventory give someone the job but doesn’t always give that person the responsibility to make the changes that ensure he or she can manage inventory appropriately.” Effective inventory management means knowing what is on hand, where it is used, how it is used and when to replace that supply. In its simplest form, inventory management tries to balance the needs and requirements of the practice with the need to minimize costs that result from obtaining and holding that inventory. Reeder suggested these tactics to control inventory. • Designate an inventory manager, who has the authority to manage the inventory. That person should go through the inventory periodically and make sure that products are shelved according to expiration date and make sure that older supplies are used first. • Stop providing unrestricted access to drugs and supplies. Bar codes, coded pharmacy and supply entries, making people sign in and out, and locking the door to the supply closet or dispensary are ways to prevent unlimited access. • Use itemized check sheets in both exam rooms and trucks to keep track of what was dispensed or used. • Record items that are used or dispensed and reconcile that list at the end of the day or week. • Use the practice management software as much as pos-

Designate an Inventory Manager Make sure that person has the authority to properly manage the inventory. Restrict Access Preventing unlimited access helps the manger keep track of supplies. Use Itemized Check Sheets Keep track of what was dispensed in the truck or exam room. Maintain Drug Logs Drug logs should be in every truck and satellite clinic and reconciled once a week. Maintain Adverse Reaction Log Keep track of adverse events and report them to the company and regulatory agencies. sible. Practice management software can be a big help, but Reeder has yet to find the perfect software for an equine practice. “We’re a weird beast,” she said. • Limit the veterinarian’s access to his or her “favorite” drug. Drugs should be chosen based on medical science, side effect profile and cost. • Maintain and establish an inventory budget. • Keep up with regulatory logs. Even in ambulatory practices, there needs to be a controlled drug log in the truck, and in the satellite clinic, and it needs

to be brought into the main clinic at least once a week and reconciled. •K  eep an adverse reaction log. Keep a log for any drug reactions that might occur in the clinic and turn that information over to the distributor and the pharmaceutical reps. Adverse events can also be reported to the FDA. “Inventory is a large expense in any practice,” Reeder said. “Successful management must address the challenges, some of which are unique to an equine practice.” MeV

TheModernEquineVeterinarian.com | July 2012

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emerging diseases

Lawsonia intracellularis organisms

appear species-specific

Pigs are not the source of infection when foals come down with EPE Don’t blame the pig when a foal

vestigated several farms with sporadic and endemic occurrence of EPE is that in closed herds the first horse(s) becomes exposed likely

comes down with equine proliferative enteropathy (EPE), a gastrointestinal disease, said Nicola Pusterla, DVM, DACVIM, of the University of California at Davis. Lawsonia intracellularis is an obligately intracellular bacterium that causes proliferative enteropathy, an enteric disease that affects both pigs and horses. “But people need to stop blaming pigs as the source of L. intracellularis infection for foals,” Pusterla said. “I believe that environmental contamination should be avoided, i.e. feed off the ground, cover feed, clean water troughs, monitor foals daily and isolate foals with confirmed EPE or signs compatible with EPE.” EPE appears to be increasing in horses, but experts are not sure whether the increase is due to more cases or just better recognition in sick foals. Most of what is known about Lawsonia infection comes from the swine industry, where it is a costly problem. “My strong belief having in-

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nonequine domestic animal,” he said. “We have established that most foals become infected without developing clinical disease, however, during this time, they are amplifying L. intracellularis organisms, and that contributes heavily to environmental contamination. This environmental contamination, similar to the shedding of Rhodococcus equi from clinically and/or subclinically infected foals, allows the exposure of more foals. Thereafter, it is a numbers game, with 5% to 15% of exposed animals developing EPE. “Why do certain foals develop EPE and others don’t? This is likely a multifactorial disease process combining known and unknown host, environmental and pathogen factors,” he told The Modern Equine Veterinarian. Lawsonia bacteria from pigs and horses with this disease are the same species and identical in every characteristic except for a few slight genetic differences, accord-

EPE appears to be increasing in horses, but experts are not sure whether the increase is due to more cases or just better recognition in sick foals. via ingestion of infectious L. intracellularis through contamination of feed and/or water originating from the feces of a wild, feral or

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the results show that Lawsonia isolates are host specific. Pig and horse isolates do not cross-infect those species,” Gebhart explained. “It is unlikely, from our research, that a horse could get the disease of proliferative enteropathy from a pig,” she said. “Equine isolates infect horses, and porcine isolates infect pigs. There does not appear to be any cross-infection or host adaptation between strains (strains being equine or porcine).” There is a swine vaccine available, but it is not labeled for use in foals. However, Gebhart and Pusterla have done extensive research with the vaccine, Enterisol Ileitis (Boehringer Ingelheim Vetmedica), and found that the vaccine protects foals against the disease. MeV

Photo courtesy of Connie Gephart

ing to Connie Gebhart, MS, PhD, of the University of Minnesota, who with Pusterla has been studying this organism for years. “We wondered if these genetic differences suggested that the horse and pig isolates of Lawsonia were species-specific, meaning that they can infect and cause disease only in the species that they were isolated from,” she said. To evaluate this, the researchers infected horses with either an equine or porcine Lawsonia isolate and then infected pigs with either an equine or porcine Lawsonia isolate. They found that only horses infected with the equine isolate and pigs infected with the porcine isolate developed clinical, serologic and pathologic signs typical of proliferative enteropathy. The results appeared recently in the journal Veterinary Research. “Cross-infected animals continued to be normal. Therefore,

Photo courtesy of Dr. Nicola Pusterla

Photo courtesy of Connie Gephart

Foal with equine proliferative enteropathy, an emerging intestinal disease primarily affecting recently weaned animals. Although disease development is sporadic, infection can become endemic on farms. Caused by Lawsonia intracellularis, signs include ventral edema, depression, fever, wasting, colic and diarrhea.

Immunohistochemical stained section of small intestine from a 7-month-old foal with proliferative enteropathy. L. intracellularis-specific antibody stains the bacteria lining the apical cytoplasm of the affected crypts (red areas). Similar staining is seen in affected pig intestines. TheModernEquineVeterinarian.com | July 2012

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News notes

By Dr. Robert M. Miller

Rescue Partnership Gives Horses a Second Chance — and we are pleased that we Horses have been silent can be part of that program,” victims of the economic Lombardi said. “We work downturn, as horse owners primarily with the Rescue are voluntarily surrendering and Restore portions of the their animals in record numprogram to determine the resbers, putting a huge burden cues’ medical needs and to get on rescue organizations. them in shape for adoption.” The relationship between Diamonds in the Rough The Oaks Veterinary Clinic in has many volunteers, but the Smithfield, Va., and the Diacost to run a quality rescue monds in the Rough Rescue is tremendous, making donain Windsor, Va., shows what tions critical. can be done to help horses “Many of the horses that when veterinary clinics partcome in to the rescue are unner with rescue organizations. Dr. Cathy Lombardi of The Oaks Veterinary Clinic and an assistant conduct an derweight and have no vac“We saw these cases on examination on a rescue horse. Dr. Lombardi partners with Diamonds in the cination records,” Dr. Lomthe rise, and a longtime client Rough of Windsor, Va., on its equine rescue program. bardi said. “This combination of ours started doing rescues makes them more susceptible, and when you look at the out of her existing boarding facilities and asked us to money allocation in a nonprofit, vaccines sometimes help her out, which we were happy to do,” said Cathy have to go by the wayside.” Lombardi, DVM, who has been with The Oaks since 2004. Lombardi and her colleagues at The Oaks reached out to Pfizer Animal Health earlier this year seeking a Diamonds in the Rough takes in as many as 20 donation of vaccines to help with their work, and Pfizer horses a month, and Lombardi has a standing weekly was glad to help. The company donated 100 doses of appointment to oversee the health care of new and West Nile-INNOVATOR + VEWT vaccine, which existing horses in the program. helps prevent West Nile virus; and Eastern, Western “Diamonds in the Rough has a program built around and Venezuelan encephalomyelitis viruses; and tetanus. the four R’s — Rescue, Restore, Retrain and Rehome “We work very closely with our veterinary partners, and when doctors at The Oaks reached out to us for help, we jumped at the chance,” says Palmer Valentine, Territory manager, equine division at Pfizer Animal Health. Vaccines not only protect against disease but also increase the animal’s chance for adoption, because that is one less expense a new owner has to undertake. “This makes adoption easier and starts the horse out on the right foot in its new home,” Lombardi said. Across the country, many rescue organizations are working to rehabilitate surrendered horses and put them in good homes. “In talking with our veterinary partners, we know that the need is there for horses across the country,” Valentine says. “At Pfizer Animal Health, we try to do our part, but there is so much that these organizations need beyond monetary donations.” If you are in Virginia and would like to get involved with Diamonds in the Rough, you can find them at www.adoptditr.org. If you are not, consider volunteering at another organization. They need your help. MeV Dr. Miller’s cartoons and videos are available for sale at www.robertmmiller.com 20

July 2012 | TheModernEquineVeterinarian.com


the FEED bag

Fatter than they look

P.Uzunova/ShutterStock

By Marie Rosenthal, MS Any veterinarian will tell you that America’s companion animals are getting too fat, and horses are no exception. Part of the problem, said Alex Dugdale, MA, VetMB, DVA, DECVA, MRCVS, is that owners frequently do not recognize that their horses are overweight, and then, once the veterinarian convinces owners to restrict the horse’s calories, they might not recognize that the dieting horse is losing weight because its body condition score (BCS) doesn’t change much in the beginning of the diet. This can make it difficult to remain committed to a diet plan. “My biggest worry with obesity is that many of us don’t recognize it,” said Dugdale, senior lecturer at the University of Liverpool School of Veterinary Medicine. “Obesity creeps up on us, as well as our animals. A horse or pony in ideal body condition should actually have easily palpable ribs.” Dugdale and her colleagues conducted a study published in the Equine Veterinary Journal [2010; 42:600610] that provided scientific evidence for managing weight loss in obese animals. They restricted food intake in five overweight or obese Welsh mountain pony mares for

3 months and monitored changes in their overall health, behavior, body weight, body fat content and BCS. They restricted daily dry-matter intake to 1% of the animal’s body mass. During the study, the researchers monitored the health of the ponies by taking weekly blood samples and observing their behavior. They weighed the ponies on a weighbridge and used a tape measure to assess heart girth, umbilical belly girth and rump width. They also used ultrasonography every week to measure the depth of the fat beneath the skin at several sites. Finally, they calculated the body fat content using deuterium oxide dilution. “We found that, on average, ponies lost 30 kg of weight over 3 months and that about half of this [weight loss] was fat, although the ponies that were fatter at the start lost a relatively greater proportion of fat,” Dugdale said. Despite losing weight, the ponies’ appearance and BCS did not change much. “This surprised us,” she said, “but highlights that once a horse or pony carries too much fat, it has to lose quite a lot before


the FEED bag

its BCS will decrease.” As expected, weight loss was marked over the first week of the trial, reflecting the decrease in gut-fill associated with feeding smaller amounts. In addition, the muscles were probably depleted of glycogen. “During the initial stages of dieting, the body uses up its glucose stores, so the muscles become depleted of glycogen, and their water content also reduces. This helps explain some of the rapid first-week weight loss.” Dugdale said. Dugdale added that owners should not overly focus on BCS to monitor weight loss, at least in the early stages of dieting. Instead, use a weighbridge, a tape measure to measure the heart girth or a weigh tape to monitor body weight.

Other issues

“Getting [the horse] outdoors and exercising is important for energy expenditure, socializing and general well-being, so grazing-muzzles are useful, but make sure the animal can drink water through the muzzle.”

“At the level of dietary restriction chosen, we were worried about inducing hyperlipidemia. However, none of our ponies became ill at all,” Dugdale said. In fact, blood test results showed that even a little weight loss was associated with improvement in insulin sensitivity status. “Obese animals often become insulin resistant,” she said. “In people, insulin resistance is associated with metabolic disorders, such as diabetes mellitus type 2, cardiovascular disease and renal and hepatic disease. In horses and ponies, however, laminitis seems to be the biggest risk.” One always worries about behavior when horses or ponies are denied access to food, but the researchers did not see any long-term behavior problems. “No long-term adverse behavioral effects were observed, but sudden severe food restriction is not a normal situation for horses and ponies, which are grazing animals — what we call ‘trickle feeders’ — and are designed to eat for at least half of each 22

July 2012 | TheModernEquineVeterinarian.com

day,” Dugdale explained. She suggested several techniques to extend mealtime in dieting horses and ponies: • Use double-layered hay nets. • If manger feeding, add obstacles, such as large stones that the horses have to work around to find their food. Other forms of environmental enrichment can reduce boredom, Dugdale added. Some horses will play with stable toys. Others may be happier in graze-poor paddocks with their friends, but it is easier to control the horse’s food intake if he is stabled. All of the ponies in the study lost some lean tissue, as well as fat, which is why exercise needs to be encouraged when possible, she said. If putting a horse on a diet, consult a veterinary nutritionist if the owner will pay for it. Then decide on the level of dietary restriction to impose, and encourage owners to follow this diet for at least 2 months. Remember to warn against giving treats. Just as people can undermine the best diet with a piece of cake, owners can sabotage a horse’s diet with applies and carrots, which contain many calories. Tell owners to weigh the food allocation, not eyeball it. Monitor the weight loss every week at the same time of Alex Dugdale day. If there is little weight loss over time, veterinarians should reassess the animal because more calories might need to be restricted. Encourage owners to exercise the animal, which not only burns more calories and encourages lean muscle mass but helps with the animal’s behavior. Exercise also can improve insulin sensitivity. “Getting [the horse] outdoors and exercising is important for energy expenditure, socializing and general well-being, so grazing-muzzles are useful, but make sure the animal can drink water through the muzzle,” Dugdale said. MeV


finish line

Owners Pledge to Race 2-Year-Olds of 2012 without Race-Day Medications Just as we were about to post this issue, The Thoroughbred Owners and Breeders Association (TOBA) announced some good news. A broad-based list of Thoroughbred owners who are members of TOBA pledged to race their 2-year-olds without race-day medications. These horses will race their entire 2-year-old season without race-day furosemide and adjunct blood thinners. Almost every horse in every race is treated just hours before they go to the saddling paddock. These medications are not medically necessary, and do not improve the long-term health of the horse. “The original purposes of permitted race-day medication were to treat horses that overtly bled from the nose and to provide a larger pool of horses available for entry at a time when racing was proliferating,” said Bill Casner, who has campaigned notable horses, such as Super Saver, Well Armed and Colonel John, among others. “Trainers and veterinarians soon recognized that horses that raced on furosemide could have a competitive advantage and now almost all horses are being diagnosed as bleeders. Racing commissions, in an effort to level the playing field and eliminate this advantage, relaxed their rules to allow furosemide for any horse. I believe the pervasive use of furosemide, and the dehydration stress it causes requiring more recovery time, has contributed to horses making fewer starts and has fueled the public’s belief that giving medication to performance horses is abusive and nefarious. Our racing industry thrived in a time prior to permitted race-day medications. Horses raced often and consistently. We are a global industry and we are out of step with the rest of the world. Race day medications are a failed experiment and it is time for us to do what is right for our horses and our industry.” Other owners who want to add their names and campaign their 2-yearolds without race-day medication can be added to the list by contacting the TOBA offices, said Dan Metzger, president of TOBA. TOBA, based in Lexington, Ky., was formed in 1961 and is a national trade organization of leading Thoroughbred horse breeders and owners. Projects managed by TOBA include the American Graded Stakes Committee, The Racing Game, Sales Integrity Program and Claiming Crown. Thoroughbred Charities of America (TCA) is the charitable arm of TOBA. TOBA is the owner of The Blood-Horse Inc., and is represented on the Board of Directors of the National Thoroughbred Racing Association as a founding member. This is great news and this magazine applauds these owners and hope everyone else follows in their path. It’s better for the horses. And let’s face it, it’s more sporting. Marie Rosenthal, MS Editor The Modern Equine Veterinarian

TheModernEquineVeterinarian.com | July 2012

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