Volume 12: Issue 1 Fall 2016 Updates Create Service Improvements Alison LaCarrubba, DVM, DABVP

In order to stay current, the Veterinary Health Center (VHC) is continually updating equipment and creating new opportunities for veterinarians and clients. If you have visited the VHC recently, you will have noticed that the parking lot for the Equine and Food Animal hospitals is under construction. We are fortunate to be the benefi- ciaries of a new building to house our ambulatory vehicles as well as classroom and office space. This building is ex- citing for those of us who scrape ice from windshields during the coldest winter months! This year the equine section is also fortunate to have been able to update our digital radiograph units, both in the clinic and in the field. I have never been so in love with a piece of equipment. Our ambulatory unit is completely Construction taking place in the Equine and Food wireless. This is especially exciting to those of us working Animal hospitals parking area is for an ambulato- in the field. We can now bring the radiograph unit to a ry facility that will house food animal and equine horse in almost any location and take films. Having no ambulatory vehicles as well provide office space cords connecting the equipment also increases safety as and a seminar room. well as efficiency. To top it off, the images are truly of the highest quality. Fall, with its cool weather and beautiful foliage, is my fa- Many of you may be familiar with the Lameness Locator, vorite time of year for riding. Now that my children are a wireless, objective lameness evaluation system created old enough to ride with me, I find myself looking forward by Kevin Keegan, DVM, one of our surgeons. Keegan is to our weekend excursions. I hope that you all are able to never idle and he has recently been working on a wireless saddle up and enjoy your time with your equine friends. system to help detect mild neurologic deficits in horses. We would like to thank all of you for your continued sup- It is not uncommon to have a horse present for lameness port of our program. Please don’t hesitate to call or contact that actually has low-grade neurological deficits. These us if you have any questions or need help with anything. mild deficits can be difficult to detect. This new system has so much potential to help us reach a more accurate If you haven’t already, please like us on Facebook so you diagnosis quickly. We look forward to seeing progress on can keep up with the current equine news, patient updates this new technology. and other fun facts: www.facebook.com/MUEquineClinic/

1 Meet the MU Equine Ambulatory Team Alison LaCarrubba, DVM, DABVP Dee Whelchel, DVM, DACVIM-LA

Alison LaCarrubba, originally Dee Whelchel works with both from New York, grew up riding the Equine Internal Medicine and hunter/jumpers and dressage from Ambulatory services. Whelchel is a young age. After graduating from originally from Atlanta, where she Cornell University with a degree in grew up riding hunter/jumpers. animal science, LaCarrubba moved She attended Emory University for to the Midwest to obtain her vet- undergraduate studies and com- erinary degree. She graduated from pleted a master’s degree in physi- the University of Missouri College ology at the University of Georgia of Veterinary Medicine in 2001. LaCarrubba complet- with a research focus on botulinum neurotoxin. She com- ed an internship in equine medicine and surgery at the pleted her DVM at the University of Georgia, followed by university and subsequently spent a year working in an a one-year internship in large animal medicine and sur- equine exclusive private practice. She returned to the uni- gery at Texas A&M University. Whelchel then returned versity in July 2003 as a clinical instructor, and in 2009 she to UGA to complete a residency in large animal internal completed the specialty boards with the American Board medicine in 2011. During her residency, she researched of Veterinary Practitioners in Equine Practice. low molecular weight heparin therapy in horses. LaCarrubba’s love of equine dentistry has inspired her Whelchel spent three years in private practice in South to continue her training in this area. In recent years she Carolina where she worked both as an ambulatory clini- has attended a variety of advanced equine dental courses, cian and a boarded equine internal medicine specialist. which has allowed her to develop specialized skills and Her experience included time in Aiken, South Carolina, expertise in this field. As the equine dentist for the univer- which is a unique multidiscipline equestrian commu- sity, LaCarrubba is excited to see all things dental, from nity that includes three-day eventing, hunter/jumpers, routine work to more complicated extractions. When she thoroughbred training centers, and Fédération Équestre is not at work, she is spending time with her husband and Internationale-level driving. Her professional interests three children. The whole family enjoys horses and riding include equine infectious diseases, endocrine disorders, together on Missouri’s beautiful trails. respiratory disease, critical care, cardiology and neona- tology. In her free time, she enjoys riding horses, biking Martha Scharf, DVM and hiking. Martha Scharf practices equine ambulatory medicine at the Equine Our interns have a special interest in working with Hospital. Scharf was born in Chi- horses and potentially going on to complete a residency, cago and grew up riding hunters/ specializing in either equine medicine or equine surgery. jumpers in St. Louis. Since mov- Every June we welcome a new crop of interns. This year ing to Columbia she has contin- our interns include Katie Bucy and Jessica Millwood. ued to ride and started to explore Katie Bucy, DVM three-day eventing. After earning a DVM at MU, she completed a rotating equine intern- ship at the university. She continues to work as a clinical Katie Bucy grew up in Westminster, Maryland. She instructor for the Equine Ambulatory Service. competed in eventing and was part of the local pony club, 4H and FFA programs. She attended Virginia Scharf spends the majority of her time instructing senior Tech for her undergraduate studies and graduated in veterinary students while providing quality medical care 2006 with a bachelor’s degree in biochemistry. Bucy for horses within the Columbia area. She is particularly then moved to North Carolina and worked as a veteri- interested in wound management and emergency care in nary technician for a few years prior to attending Ross the ambulatory setting. Scharf works closely with the re- University School of Veterinary Medicine. ferral clinicians in the Equine Hospital to provide supe- rior care to horses. Continued on page 3

2 Potentially Serious, Choke is Manageable Martha Scharf, DVM material is observed coming from Choke, also known as esophageal Although uncommon, long-term, the nostrils and mouth. Although the obstruction, is a common condi- unnoticed obstructions can prog- horse may initially try to eat or drink, tion of horses that occurs when the ress to esophageal rupture, shock, these attempts generally exacerbate the drainage and lead to coughing. esophagus (the flexible, muscular severe infection and death. tube from the mouth to the stomach) Often, the horse is anxious, repeat- becomes blocked. Unlike choke in edly attempting to swallow, gagging, corn cobs. The mass becomes caught humans, which refers to blockage of and coughing. in the esophagus, partially or com- the airway, horses are typically able pletely obstructing the passage of If the obstructing object is large and to breathe while choked. However, more food. in the neck portion of the esophagus, with time, their airway may become it may be palpable as a firm, painful compromised by regurgitated food Horses can be predisposed to choke mass on the left side of the neck. Fol- and saliva. As a result, emergency by rapid eating, dental disease, in- lowing the initial period of acute dis- veterinary care should be sought im- ability to swallow normally (caused tress, many horses become calmer but mediately upon discovery of a choke by neck injuries, neurological disease, will continue retching and maintain to prevent significant complications. or scars or masses in the esophagus), a downward extension of their neck or access to excessively coarse feeds, The most common cause of choke and throat. With time, dehydration such as straw or dry beet pulp. Choke is a mass of swallowed food that is and depression will occur. Although can affect horses of all ages, but it served in pieces that are too large, uncommon, long-term, unnoticed is commonly diagnosed in geriatric improperly chewed, too coarse, too obstructions can progress to esopha- horses due to poor dentition, neuro- dry, or that swell after swallowing. geal rupture, shock, severe infection logical abnormalities or both. Esophageal obstruction has also been and death. reported with foreign objects, such Choke is most often discovered fol- as shavings, riding crops, wood and lowing a feeding when saliva and feed Continued on page 4

Interns, Continued from page 2 Jessi Millwood, BMVS, MRCVS Bucy’s clinical year was com- pleted at RUSVM’s affili- Jessi Millwood grew up ate school, Oklahoma State on a hobby farm in Ruth- Center of Veterinary Health erfordton, North Carolina. Sciences, where she gained She attended the University experience working with the of North Carolina at Wilm- western riding disciplines. ington for undergraduate She graduated in 2015 and studies in marine biology completed a yearlong in- and Spanish. She is a 2015 ternship at New England Equine Practice in Pat- graduate of the University of Glasgow School of terson, New York. During this internship she gained Veterinary Medicine. She went on to complete a experience working with horses trained in the hunt- one-year internship in large animal internal medi- er/jumper, eventing and dressage disciplines. cine at the University of Saskatchewan. Her professional interests include surgery and Millwood’s clinical interests include ambulatory lameness evaluations, and she hopes to pursue a and internal medicine. She is interested in pursu- surgical residency after the completion of her in- ing a residency in internal medicine and a profes- ternship at Mizzou. sional career in academia, or returning to a mixed animal private practice. In her free time, she enjoys hiking, reading and completing various crafts. In her free time, she enjoys traveling and spend- ing time with family, friends and her dog, Acacia.

3 Choke, continued from page 3 Esophageal obstructions can often be treated successfully by a veteri- narian. Sedatives and muscle relax- ants are administered to relax the muscle of the esophagus and lower the head to prevent inhalation of food and saliva into the lungs. In mild cases, this alone may allow the passage of the blockage into the stomach. Passage of a stomach tube can confirm that the obstruction has been relieved. In more severe cases, water through the stomach tube can be used to lubricate the blockage and gently push the obstruction to- ward the stomach. In some cases, this can be a long, slow process to wash the obstruc- tion out without damaging the esophagus. Endoscopy (a video camera into the esophagus) can be used to evaluate the blockage and the health of the esophageal mu- cosa. Severe occurrences may also A filly that had inflammation of the intestines, is now in good require anesthesia to relax the horse health, thanks to the quick response of the owner, who contacted completely or surgery to relieve the the MU Veterinary Health Center for assistance. blockage. Rarely, cases may not be resolved despite all efforts. Sick Filly Saved Due to After resolution of the blockage, most horses require rehydration with Alert Owner, Team Care fluids and electrolytes. For days after- ward, the esophagus is often painful, Case Study requiring the administration of anti- Alison LaCarrubba, DVM, DABVP inflammatory medications and feed- an enema was given and a fair bit of ing of wet mashes of pelleted feed fecal material was passed. The filly and grass. Many horses are also treat- he Equine Ambulatory Service T was given mare’s milk via nasogastric ed with antibiotics to prevent pneu- was called to evaluate a neonatal tube since she was not nursing well, monia that may result from inhaled quarter horse filly on a mid-March and an antibiotic was initiated. A few food and saliva. afternoon. The filly had been born at approximately 4 a.m. that day. The hours later, the filly was lethargic, re- Following recovery, horses should filly would not suckle for more than luctant to stand and not nursing well. also be examined for any predispos- a few seconds at a time. The owner It was decided that referral to the ing factors such as dental disease, ab- bottle-fed colostrum to the filly, and VHC was the safest option to save normal swallowing, resulting esopha- it was noted that the filly passed me- the foal. geal scars or other abnormalities, or conium earlier in the day. On presentation at the VHC, the food bolting behaviors. Upon examination by the Ambula- filly was showing signs of colic, ly- While choke can be a serious problem, tory Service, the filly was quieter than ing down and rolling onto her back. proper management can markedly re- expected, but showed some vigor. She was in good body condition and duce the risk of long-term complica- The physical examination parameters weighed 95 pounds. Her heart and tions, and early detection and treat- were within normal. Shortly after the respiratory rates were increased, but ment can typically resolve the problem examination, the filly was seen tail rectal temperature was normal. Her without further complication. flagging and straining to defecate, so Continued on page 5

4 Case Study, continued from page 4 heart and lungs ausculted normally. What Horse Owners Should Normal gastrointestinal sounds were present in all four abdominal quad- Know About Neonatal Sepsis rants. Her feet were cool to the touch and pulse quality was weak. The ab- Dorothy Whelchel, DVM, DACVIM-LA domen was mildly distended. dummy foal syndrome. Prematurity of the foal (birth at less than 330 days Foals that show signs of distress and ny horse owner who plans to A of gestation), prolonged delivery or lethargy can decompensate quickly. breed mares and raise foals should dystocia (longer than 30 minutes de- We placed an intravenous catheter know about neonatal sepsis. Neonatal livery), red bag delivery, meconium and obtained blood to evaluate the sepsis is a significant cause of mortal- aspiration during delivery, as well as foal’s health status. A complete blood ity and morbidity in foals of less than prolonged time to stand and suckle count revealed a severely decreased seven days of age. Early recognition after birth, are all considered risk fac- white blood cell count showing sig- can be life saving. By definition, sep- tors for neonatal sepsis. nificant compromise as well as mild sis is an identified or suspected infec- tion along with a systemic inflamma- dehydration. Transabdominal ultra- Owners should take note if foal- tory response syndrome, which may sound showed a moderate amount of ing events follow the “1, 2, 3 Rule,” lead to organ dysfunction and shock. fluid in the abdomen and thickened which means that the foal should be In neonatal foals, localized bacterial small intestinal walls. A fluid sample standing within one hour of birth, infection of the umbilical structures, was obtained from the abdomen and suckle WELL within two hours of joints and lungs, and diarrhea are it showed significant abnormalities. birth, and the mare should pass her especially associated with sepsis. In placenta by three hours after deliv- Based on the initial evaluation, the many respects, the clinical syndrome ery. If ANY of these events do not filly was diagnosed with presumptive caused by sepsis is largely due to the occur within the expected time, own- sepsis and peritonitis secondary to foal’s immune response to infection, ers should call a veterinarian. enterocolitis, or inflammation of the resulting in a massive release of in- intestines as well as the area around flammatory and anti-inflammatory Close monitoring of a foal’s behav- the intestines. mediators that may further alter the ior and nursing is important as the function of the immune system, the foal acquires passive immunity from Initial therapy consisted of plasma microvasculature, blood coagulation ingestion of the mare’s colostrum in to boost the immunity of the foal and the endocrine system, eventually the first six to 12 hours of life. If the by providing antibodies, intravenous progressing to multiple organ failure foal does not get adequate intake of fluids for rehydration and cardiovas- and death. colostrum and absorption of mater- cular support, broad spectrum anti- nal antibody, the risk for infection microbial therapy and a gastro pro- Our understanding of sepsis con- and illness significantly increases for tectant. Within the first 48 hours of tinues to evolve in both human and the foal. In fact, decreased nursing, treatment, the filly showed significant neonatal foal medicine; however, risk increased periods of lying down, and improvement and was consistently factors for equine neonatal sepsis partial or failure of passive transfer suckling the mare without assistance have been identified and warrant the are three of the most important risk or need for supplemental nutrition. awareness of the horse owner. factors of neonatal sepsis. This case illustrates that it takes a Historical risk factors include health A diagnosis of neonatal sepsis is made team to quickly and correctly diag- problems of the mare or manage- based on physical examination find- nose a sick foal and provide the nec- ment issues during pregnancy, prob- ings, evidence of an infection based essary intensive care to give the foal lems during delivery of the foal and on the foal’s white blood cell count, the best chance at life. This filly’s abnormalities in the foal’s behavior identification of localized infection, story ended on a positive note due to shortly after birth. Maternal illness and blood cultures to detect bacteria the fast action of the owner noticing during gestation, twin pregnancies, within the blood. Physical examina- that there was a problem, as well as fescue exposure in the last 60 days of tion findings suggestive of sepsis in- referral to the VHC, which was able gestation, placentitis (often evidenced clude abnormal mentation; signs of to provide around-the-clock care by premature udder development, cardiovascular shock; evidence of in- with a team approach. The filly was fever and vulvar discharge) and pre- fection such as swollen joints, heat or discharged within a week and went mature lactation may predispose the swelling of the umbilicus, evidence of on to thrive, with no complications neonatal foal to sepsis or other life- or untoward effects. threatening complications including Continued on page 6

5 Sepsis, continued from page 5 respiratory disease such as pneumo- passive transfer has occurred, and if nia or the presence of diarrhea; and the foal’s IgG concentration mea- petechial hemorrhages along mucosal sures low, the veterinarian will likely surfaces of the gums, eyes, nose or recommend administration of equine vulva of the foal. Fever (body tem- plasma to increase the foal’s immu- perature greater than 102.5 F) may be nity. If the veterinarian finds any present, while some foals with neona- concerns, they may recommend ad- tal sepsis may even have a low body ditional testing, antibiotic treatment temperature (less than 99 F). or referral to an equine hospital. If any evidence of sepsis is noted, Take home points Wolf Tooth prompt and appropriate broad-spec- • Good husbandry of broodmares trum antibiotic therapy is essential. may reduce the risk of neonatal Delayed administration of antibiotic sepsis and illness. Talk to your Removal is treatment can have a significant, neg- veterinarian about appropriate ative impact on survival. vaccination and deworming pro- Best Done in tocols as well as nutrition for the Additional therapies include admin- pregnant mare. After breeding, Young Horses istration of intravenous fluids and have a veterinarian perform an Alison LaCarrubba, DVM, DABVP plasma. Ill foals may require extensive ultrasound examination to con- supportive care if they are not able to firm pregnancy and check for stand on their own, and foals suffer- twin pregnancies at day 14 post he wolf tooth is the lay term used ing from septic shock may require ag- T known breeding or ovulation to describe the first premolar in the gressive cardiovascular support. The dates. Avoid exposure to fescue horse. It is typically a small tooth, level of care required for these foals grass or hay in the last 60 days of located most commonly just in front often warrants referral to an equine gestation as this may cause prob- of the first upper cheek teeth. The hospital capable of 24-hour care with lems with delivery, placentitis and wolf tooth is what we call a vestigial board-certified specialists in equine milk production. tooth, or a remnant from the past, internal medicine or critical care. has no real function, and is not used • Notify your veterinarian prompt- in chewing. When sepsis is not recognized early ly if you note any signs of mater- or treated appropriately, the progno- nal illness during gestation in- Horses can have wolf teeth on the sis for survival is poor. Fortunately, cluding fever, vulvar discharge or lower arcade as well, but this is un- during the past few years, prompt de- premature udder development. usual. The number, size and exact tection, early antibiotic therapy and location of wolf teeth varies from advances in equine neonatal medicine • Know the “1, 2, 3 Rule” and call horse to horse. Approximately 40 to have improved the prognosis for foals your veterinarian if these steps do 80 percent of horses actually have with sepsis. However, even in the face not occur on schedule. wolf teeth and these teeth typically of aggressive care, many foals still • Schedule a new foal examination erupt by 6 to 18 months of age. succumb to the disease. with your veterinarian even if Uncommonly, wolf teeth do not your foal appears normal. Have a One of the most effective preventa- erupt properly and remain just be- veterinarian check your foal’s IgG tive measures horse owners can take low the surface of the gum. This is levels during this visit to confirm against neonatal sepsis is to have a what we call blind wolf teeth and passive transfer. This can be ac- veterinarian perform a new foal ex- these unerupted teeth likely cause complished with a stall-side kit amination between 18 and 24 hours the most problems with bitting and called a Snap® Foal IgG Test. of age, even if the foal is apparently overall discomfort. healthy. At this time, the veterinarian • If your foal shows signs of de- Whether to remove wolf teeth has will perform a thorough physical ex- creased nursing, increased recum- become a somewhat controversial amination of both the foal and mare, bency, weakness, abnormal be- topic. The horse world is full of tra- examine the mare’s placenta, which havior or signs of infection, such dition, and removing wolf teeth in has been saved by the owner, and take as diarrhea, swollen umbilicus or young horses is part of that tradition. blood to measure the foal’s IgG con- swollen joints/lameness, call your centration. This blood test ensures veterinarian immediately. Continued on page 7

6 Wolf Tooth, continued from page 6 There is no reason not to remove these vestigial teeth prior to starting a young horse in training. This can eliminate the potential for irritation and head shaking by a young horse in training. These teeth are best re- moved prior to 3 years of age, as they can become well-rooted with age, increasing the likelihood of fractur- ing the tooth when removing it. Although the bit will never reach far enough back in the mouth to touch the wolf teeth, the soft tissues of the mouth, lips and gingiva can be pulled into a sharp wolf tooth caus- ing irritation and pain. Also, it can be difficult to create an optimal bit seat on the first cheek teeth with the wolf tooth in the way. Unerupted, or blind wolf teeth cause Treatment Options Are the most problems. These teeth tend to be displaced forward in the mouth and sit in a more horizontal plane, Varied for Cellulitis rather than vertical. These unerupt- Katherine Bucy, DVM ed teeth may actually make contact with the bit and can be associated a focal area of infection, this can be with pain. Sharp or displaced wolf Cellulitis is severe inflammation cultured, but the diffuse nature of the teeth can cause pain and even ulcer- of the subcutaneous tissues, which disease often makes culture difficult. are the tissues located just below the ations when the pressure of the bit Once a horse has developed celluli- skin. The cause of the cellulitis of- is applied. tis, the likelihood of a future recur- ten is unknown, but may be related rence increases. It seems that the To remove wolf teeth, the horse is to bruising from trauma and sub- lymphatics can be damaged, leading sedated, a speculum placed, and a sequent bacterial infection. Some horses to recurrent bouts of painful local block used to desensitize the common causes of cellulitis are cellulitis. Treatment will vary with teeth being removed. The gingiva pastern dermatitis, also known as the severity of disease, but support- around each tooth is gently elevated "scratches"or "mud fever," wounds, ive care will include the following: on all sides, being careful not to ap- parasitism, and blunt trauma. Cellu- • Hydrotherapy: cold hosing the ply too much pressure, which can litis usually begins as a slight swelling swollen limb for 15 to 20 min- cause the root tip to fracture. of the affected limb. If the condition utes twice per day. After hosing, goes untreated, it can progress un- Horses tolerate this procedure well dry the limb as much as possible. til the area becomes hot and painful and can be ridden in the same week An antibacterial shampoo may be to the touch, and lameness develops as the removal. If there is any ques- helpful during the first cold hos- — sometimes significant lameness. tion of whether or not a wolf tooth is ing session. Some examples are The skin over the affected area may causing a problem, it is not difficult povidone iodine shampoo and begin to weep fluid, and the horse to eliminate that as a potential issue. chlorhexidine shampoo. may develop a fever. If your horse is • Wrapping or sweating the limb: The extraction of wolf teeth is com- showing any of these signs, immedi- Wrapping the limb in a standing mon, typically uncomplicated, and ate attention is recommended. will allow horses to get back to the or stack wrap may significant- business of riding without distraction. The diagnosis of cellulitis is typically ly reduce swelling in the limb based on history and clinical findings through compression. of heat, pain, swelling, fever and pos- sibly an associated wound. If there is Continued on page 8

7 Equine Simulators: The Wave of the Future in Veterinary Medicine Alison LaCarrubba, DVM, DABVP This past year we Veterinary simulation models are were fortunate becoming the wave of the future in enough to acquire a veterinary colleges. These models lifelike horse head possess characteristics that mimic the that allows the stu- textures and feel of live animals. dents to practice intravenous injec- Simulated models or simulators allow tion, intramus- veterinary students to build confidence cular injections, and fine motor skills before caring for dental blocks, and live animals. The models bridge the nasolacrimal duct gap between what students learn in flush. We also have the classroom and what they need to a model of a horse be able to do in the clinic setting. limb and hoof that Working with simulators is an excel- allows students lent first step to building confident to practice taking Simulators allow students to develop clinical and capable veterinarians. shoes on and off skills before working with animals. and use common communications. This sort of simu- There are a variety of simulators tools, such as hoof testers and hoof lation is proven to boost confidence that allow students to practice su- knives. The students are able to de- in our students prior to actual client ture skills, injections, nerve blocks, velop techniques and practice skills in interactions. reproductive tract palpation and a safe, low-pressure setting. We are excited about the prospects other minimally invasive procedures. During the past couple of years, cli- that the different variety of simula- The models are becoming so lifelike, nicians at the VHC have been using tors offer, whether models or client there is now a full-sized horse colic the simulation lab designed for the interactions. We are hopeful that the simulator. The horse is modeled af- MU School of Medicine to practice VHC will be able to acquire the life- ter a 15-hand quarter horse and al- client communications in an envi- size colic simulator, which will allow lows students to practice rectal palpa- ronment that allows for feedback our students to begin working on the tion with a complete gastrointestinal and constructive evaluations. The skills needed to be a successful equine tract, along with other common pro- students are presented with a sce- practitioner early in their careers. cedures, such as venipuncture, intra- nario in which an actor posing as a If anbody would like to help the Eq- muscular injections, and abdominal client brings an animal to them and ine Service acquire a simulator or taps — procedures that are all com- they have to perform an examination support our other work, please con- monly performed during a routine while answering the client’s questions tact our Office of Advancement at colic examination. and generally handling the client 888-850-2357.

Cellulitis, continued from page 7 To prevent cellulitis, follow these • Contact a veterinarian if any • Hand-walking: Walking is ben- suggestions, and never hesitate to swelling does not resolve with- eficial in cellulitis cases to im- call with any questions: in 24 hours from when it is prove blood flow to the area and • Examine all limbs and thor- first noticed, or if you have any decrease swelling. oughly clean any wounds as soon concerns about the welfare of your horse. In addition to supportive care, broad as possible. spectrum antimicrobial therapy is • Avoid frequent bathing of the As a general rule, the earlier a treat- typically required to control infec- legs as this can dry out the skin ment protocol is started, the more tion, along with anti-inflammatories and cause small cracks in the quickly the horse will return to op- to control pain and swelling. skin barrier. timal health.

8 Intestinal Parasite Control Demands Tailored Approach for Mature Horses Jessica Millwood, BVMS, MRCVS

Unfortunately, there is no one- size-fits-all program for intestinal parasite control, therefore, each farm or stable (with veterinary guidance) should develop its own program tai- lored to the specific needs of the farm or stable and each animal. In general, all horses should be on a basic foundation of anthelmintic treatments, which consists of one or two yearly treatments to target large strongyles, tapeworms, bots and nematodes (Habronema spp and Dra- chia spp. responsible for causing sum- mer sores). Further deworming treat- ments should target horses with high strongyle contamination potential and should focus on control of cya- thostomins at a time when mucosal burden is at its peak, such as toward the end of grazing season. • Season — Parasite activity may Performing a fecal egg count (FEC) be limited or peak during certain within the optimal temperatures for Goals of a parasite temperatures or seasons. cyathostome shedding (45 to 85 F), control program • Travel — Travel can be stressful and after the effects of the last de- 1. Minimize the risk of parasitic dis- and may decrease immune sta- wormer administered are completely ease tus at a time when there is an in- gone, will allow your veterinarian to 2. Control parasite egg shedding creased exposure to parasites by examine your horse’s feces for the 3. Maintain efficacious drugs and other infected horses. presence of worm eggs, to identify avoid further development of an- • Pasture Load — Shedding of and count those eggs, and to catego- thelmintic resistance parasites by grazing horses will rize your horse into the appropriate increase pasture exposure and level of shedder group to allow for To achieve these goals, knowledge pasture burden, which may lead the most targeted deworming strat- of the magnitude of egg shedding of to increased number of parasites egy for your individual horse. individual horses must be acquired. that can infect your horse. This knowledge can be gained by If you do not wait a suitable period performing periodic fecal egg count Identifying routine of time following deworming treat- surveillance. ment, the FEC will only reflect the deworming requirements efficacy of the last dewormer used in- Many factors affect the worm load of Horses that graze together generally stead of measuring the ability of your a horse: share the same parasite population; horse's immune system's ability to • Age — Foals and young horses however, there are huge differences regulate cyathostomin egg shedding. are more susceptible to certain in their levels of strongyle egg shed- To evaluate the egg shedding sta- parasites; immune status of hors- ding. Generally, within any group of tus in mature horses, a fecal sample es changes over time. mature horses (older than 3 years), 80 should be collected a minimum of • Location — Some parasites may percent of the parasite egg burden is four weeks beyond the egg reappear- be more common in certain areas shed by only 20 to 30 percent of the or climates. adult horses in that group. Continued on page 10

9 Parasites, continued from page 9 ance period for the last drug used. Currently recommended thresholds are based largely on the opinions of a majority of equine parasitologists, and as such, could change as more data are collected and analyzed. Egg shedding categories for most horses remain consistent; however, some horses may switch categories, especially those with FECs near cut- off values. In general, it is advised to classify adult horses to the three strongyle contaminative groups based on more than one egg count performed at one time. Repeat FECs should be performed every six to 12 months. Assuming the horse stays within the same classification, cur- rent recommendations include three FECs every six months before reduc- ing to every one to two years. praziquantel n To perform the FECRT, a • Fecal egg counts can also be re- fecal sample is collected prior to Below are the guidelines used for peated more frequently through- deworming. The anthelmintic is classifying horses on the basis of out the year at intervals based on administered and a fecal sample is strongyle egg contamination poten- the last dewormer used: collected 14 days post-treatment. tial and deworming recommenda- n Four to five weeks after fen- The number of eggs in the pre- tions until the next fecal egg count: bendazole (Panacur, Safe-Guard) treatment and post-treatment fe- cal samples are used to calculate n Four to five weeks after pyr- Fecal Egg Count Results the percent reduction in FEC antel (Strongid) for each horse individually. The and Recommendations n Six to eight weeks after iver- mean reduction for all horses • Low Shedder — fewer than 200 mectin (Ivercare, Zimectrin) tested is then calculated to deter- eggs per gram feces: deworm n 10-12 weeks after moxidectin mine the percentage reduction at twice yearly (approximately every (Quest) six months) the farm or stable. This value is • Moderate Shedder — 200 to 500 • Fecal egg count reduction test then used to make inferences re- eggs per gram feces: deworm n The efficacy of the deworm- garding the presence or absence four times yearly (approximately ers used (against strongyles and/ or drug resistance.

every three months) or ascards) on each farm should • Heavy Shedder — more than 500 be evaluated at least every three Recommendations for eggs per gram feces: deworm six years using the fecal egg count fecal sampling, storage times yearly (approximately ev- reduction test (FECRT) to help Samples should be: ery 2 two months) determine if there is resistance to • normal feces — diarrhea samples • Horses with fecal egg counts these products. can be tested qualitatively but greater than 200 eggs per gram n It is recommended to include cannot be used for FEC; feces should be dewormed at the at least six horses in a FECRT • manure that is as fresh as possi- time of testing. on each farm, always recruit the ble, ideally less than 12 hours old; • All horses should be dewormed at horses with the highest possible • refrigerated as soon as possible, least twice yearly as follows: pre-treatment egg count for the but NEVER frozen; n Spring: ivermectin or mox- FECRT, do not deworm horses • stored in airtight and leak-proof idectin within the last eight weeks prior containers or plastic bags; and n Fall: ivermectin plus pra- to FECRT, and interpret results • tested within seven days of col- ziquantel or moxidectin plus with care. lection.

10 Horses Susceptible to Skin Issues from Mild to Life-Threatening Alison LaCarrubba, DVM, DABVP

The skin is the body’s largest or- gan. The skin serves many important functions yet it is often overlooked or underappreciated. Skin serves as a barrier to the environment, plays a critical role in thermoregulation and is pivotal in supporting a healthy immune system. Skin problems can range from annoying dermatitis to life-threatening tumors or congeni- tal conditions and everything in be- tween. Many horse owners can ap- preciate the myriad problems that affect their horse’s skin. Dermatitis literally means inflamma- tion of the dermis, or skin. We tend to many dermatitis cases during the wet times of the year. Certain hors- for this problem includes topical sions that appear to be non-healing es are predisposed to dermatitis of antiseptic soaks using products such wounds, most often noted the limbs, the distal limbs, which often affects as betadine or chlorohexadine, along lips and third eyelid of the horse. the sensitive white-haired or pink- with removing these horses from wet This condition is also termed "sum- skinned areas of the limbs the most. environments. Good-quality groom- mer sores" and is self-limiting in that There are many names for dermatitis ing will help to remove the dead skin it resolves during the winter months. of the lower limb, such as "scratch- and scabs and hasten the recovery pe- If recognized, it should be treated es," "mud fever," and "dew poison- riod. Be sure not to share brushes and with appropriate deworming, and ing." Basically, when exposed to a combs between horses with dermati- possibly adjunct topical anti-inflam- wet environment for a long period of tis to reduce spread. matory therapy. time, bacteria and fungal organisms Other issues that affect the skin can Horses can also develop more seri- colonize these sensitive areas creat- be associated with insect hypersen- ous problems associated with the ing heat, pain and swelling. Affected sitivity and parasitism. This can be skin, such as tumors, including squa- areas must be cleaned with anti-bac- a real problem for sensitive hors- mous cell carcinoma, sarcoids and terial soap, treated with anti-bacterial es during the spring and summer melanoma. Squamous cell carcinoma and anti-fungal ointments, and most months. Some horses will develop is a type of skin cancer associated importantly, kept clean and dry to significant skin reactions and nodule with ultraviolet radiation, most com- prevent further infection. formation to tick bites. Other horses monly affecting horses in areas of Less commonly, these infections need will have hypersensitivity reactions light or pink (unpigmented) skin. We to be addressed with additional sys- to fly bites, even to the point of de- most often find these tumors around temic antimicrobial therapy. Along veloping hives. When this is associ- the eyes, face and genitalia. The best the same lines, horses frequently ated with the biting midge, we use way to protect against squamous cell exposed to rain or immunocompro- the term "sweet itch." carcinoma is to avoid direct sunlight during the summer months, and mised, can develop fungal dermatitis Fly sheets can be helpful, and leaving when there is snow on the ground, over their back. They develop the ste- the horses in stalls with a fan during use an ultraviolet protection fly mask reotypical crusting lesions associated the times of greatest exposure can and sun block, turn horses out at with a well-known fungus called Der- also be helpful. Certain parasites, matophylus congolense. The treatment such as Habronema, cause skin le- Continued on page 12

11 College of Veterinary Medicine University of Missouri 900 East Campus Drive Columbia, MO 65211

Skin, continued from page 11 night and keep them stalled during agnosis is typically based on clinical the day. signs in a gray horse and we often re- frain from treatment unless a tumor Sarcoids are the most common skin is growing significantly, ulcerated tumors of horses, accounting for one- or in a problematic area, such as the third of all tumors reported. Sarcoids eyelid. There are a few options to try are locally invasive and may be asso- ciated with an area of previous trau- and induce tumor regression, but at ma. They are also associated with a this point there is no gold-standard virus that affects cattle, so exposure treatment. We are hoping this will to cattle or living in a field once in- change during the next few years as habited by cattle can be a predispos- there is some promising research in ing factor as well. There is no sex or this area. breed predilection, but young horses This article offers a brief overview of are at increased risk. This type of tu- some common skin problems, but it mor has a predilection for the head, Aging gray horses are at a significant is not comprehensive. There are, of eyelids and limbs, although they can risk of developing melanomas. Up to course, less common skin conditions certainly be found at any location on 80 percent of gray horses older than associated with immune-mediated the horse. 15 develop melanomas. disease, other less common types of Although sarcoids do not metastasize, The common locations for melano- cancer and hypersensitivity issues. these tumors are locally invasive, dif- mas to develop are in the perineal ficult to fully excise and typivally re- region (around the anus/vulva) and If your horse develops a skin lesion quire multiple follow-up treatments under the tail head, although they and you are unsure of the next step, to chieve full resolution. can develop in other locations. Di- please call us at 573-882-3513.

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