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Case Study:Eye Problems Demand Immediate CareThunderis a 13-year-old mixedbreed pony that presented to theequine ambulatory service for an eyeinjury. Thunder’s owner noticed thathis eye was cloudy and tearing andcalled for an appointment immediately. Upon presentation Thunderwas bright and alert, although it wasobvious there was a problem with hisright eye. Further examination of theeye revealed excessive tearing, diffuseopacification of the cornea (the eyelooked white and cloudy), a cornealulcer present near the medial canthus(toward the nose) and a brown spot atthe center of the ulcer.retina was intact. If the retina had detached at the back of the eye, then wewould be unable to preserve vision.The retina was found to be in the correct location. Although many horsesThe ambulatory team was con- and ponies go on to have a long andcerned that the brown spot in the productive lives with only one eye,center of the ulcer represented a place the owner elected to attempt to savewhere the eye had ruptured. We were the eye and preserve vision. Thundernot sure if the brown pigment rep- was immediately taken to surgery.resented Thunder’s iris protrudingDuring an hour and a half of surthrough a defect in the cornea, or ifgery, using a microscope to visualizeit was a foreign body. Either way wethe cornea, a splinter was removedknew that this was a serious problemfrom Thunder’s eye and a patch of tisthat needed immediate attention ifsue was sutured over the defect in thethe eye was going to be saved.cornea. Thunder recovered uneventThunder was referred to the Veteri- fully from anesthesia and was able tonary Medical Teaching Hospital for walk back to his stall by early evening.examination by the ophthalmology Although the splinter was removed,service within hours of the initial call. we were still unsure if Thunder wouldThe specialists confirmed the presence be able to overcome the severe infecof a corneal ulcer and a severe infec- tion. To facilitate treatment of thetion in the eye, along with the pig- eye, a device called a sub-palpebral lament at the center of the ulcer. They vage tube was placed under the lowersuspected a foreign body, such as a eyelid. This tube allowed all of thepiece of wood, although this could eye medications to be given throughonly be confirmed at surgery. An ul- a long tube which coursed down thetrasonographic examination was per- neck and was tied into the mane. Theformed on the eye to determine if the eye medications were given as freCollege of Veterinary Medicine quently as every two hours over thefirst days of treatment, so the horsereally appreciated this tube. Thunderwas also started on systemic antibiotics and pain medications.At one week post surgery, Thunderstill had some pain and inflammation,but the infection was under controland the surgery site was healing well.The eye continued to be treated aggressively to prevent infection andpromote healing, but Thunder washome and the prognosis was good.Six weeks after surgery, Thunder’s eyehad healed with great use and minimal scarring.Special thanks goes to the ophthalmology service for providing promptand skilled service and turning a badsituation into a positive experiencefor client and patient.All of us who work with horsesknow just how sensitive they are andjust how quickly things can go wrong.We can’t impress upon you enoughthe importance of having any problem associated with the eye examinedas soon as possible.University of MissouriPage 5

EquineMetabolicSyndromeAn EmergingEpidemicThe lifestyle of contemporary, domestichorses differs greatly from the nomadic,grazing existence in which they evolved.The same slow metabolism that onceserved as an evolutionary advantage forsurvival on poor-quality forage can lead todangerous weight gain and glucose-toxicitywhen combined with modern, energyrich feeds and limited exercise. Horsesclassified as “easy-keepers” appear virtuallyimmune to even the most drastic calorierestriction. Unchecked, their seeminglyunstoppable weight gain may lead to aseries of potentially serious consequencesand a condition referred to as equinemetabolic syndrome.unpredictable cycling pattern. And, mostdevastatingly, chronically afflicted horses areoften diagnosed with laminitis, or founder.The effects of equine metabolic syndromestem from a generalized resistance to insulin,similar to type II diabetes in people. Insulinis a normal, pancreatic hormone responsiblefor transport of high levels of glucose out ofthe bloodstream for subsequent use by thebody’s cells. However, a horse with equinemetabolic syndrome has a decreased responseto insulin, caused by fat-derived hormonesand an inherently low metabolism. Thisinsulin resistance allows toxic levels of glucoseto build in the blood stream. Laminitisis often the end result of chronic insulinresistance and hyperglycemia, although theEquine metabolic syndrome is triggered mechanism by which this occurs remainsby excessive consumption of high-quality largely unknown.feeds, leading to chronic elevations inEquine metabolic syndrome is typicallyglucose levels. These horses are commonlyoverweight, even on very little feed. first identified in middle-aged horses,This weight gain is often not uniformly but has been seen in horses 6-20 yearsdistributed, but rather focally deposited old. Although seen most commonly inin the crest of the neck, shoulders, rump, pony breeds, Spanish mustangs, Peruvianat the tail head, and in the sheath of male Pasos, Paso Finos, European Warmbloods,American Saddlebreds, and Morgan horses,horses. Additionally, affected mares canContinued on page 7be hard to breed due to an abnormal andEquine Ambulatory News Fall 2008Page 6

Metaboliccontinued from page 6equine metabolic syndrome can affectany breed. Your veterinarian canperform the definitive test of equinemetabolic syndrome – a glucosetolerance test. This test involves aseries of blood draws to assess glucoseand insulin levels after intravenousglucose administration.While no specific medicationsexist to treat equine metabolicsyndrome, several strategies can beemployed to prevent or reduce theeffects of the condition. Primarily,a low-carbohydrate diet should beestablished to reduce the intake ofsimple sugars. The diet should consistof mostly hay and, if necessary, nonstarch alternative feeds (beet pulp),never allowing these horses access tograin or unlimited pasture.would be prudent to run an analysisof the NSC content. The safest hayfor affected horses has, on average,less than 10 percent NSC. A way todecrease the amount of sugar in thehay is to soak hay for one to twohours prior to feeding. Be aware thatsoaking hay for too long can resultin mold formation which would bedetrimental to the horse’s health.increased exercise can help affectedhorses to ward off obesity and caneven improve their insulin sensitivity.Finally, while there is no definitivecure for laminitis, foundered horsescan be carefully managed by yourveterinarian and farrier throughcorrective shoeing, restricted turnout and pain control.Fortunately, management of equineFor turn-out, affected horsesshould be kept on a dry-lot or in a metabolic syndrome is possible andWhen feeding hay to horses affected grazing muzzle to prevent excess can significantly improve the qualityby equine metabolic syndrome, it consumption of grass. Additionally, of life for affected horses.Grazing Tips for Horses with Equine Metabolic Syndrome, LaminitisAs Equine Metabolic Syndromeand insulin resistance continue toincrease in significance among ourhorse population, it is important tolearn how to better care for and feedour affected equine friends. Recently, Kathryn Watts spoke on thetopic of grazing horses with EquineMetabolic Syndrome (EMS) at theWhen feeding obese horses or horsessuffering from EMS and laminitis,it is important to utilize feeds thatprovide balanced protein and mineral content, but are low in nonstructural carbohydrates (NSC).Non-structural carbohydrates consist of simple sugars, disaccharides,fructans and starch.Missouri Veterinary Medical Association equine summer continuingeducation meeting. Watts has morethan 25 years of experience in agricultural contract research and consulting. Much of what was writtenhere has been taken from her lecture and can be found online at herWeb site, www.safergrass.org.Much of the grass we see in Misver the last three decades re- improve cold and drought tolerance. souri is considered cool season grass.search on forage quality has been Only recently have we realized that Examples of cool season grasses indirected toward the production ani- perhaps the characteristics that sup- clude fescue, brome, orchard grass,mal that aims to increase nutrient port quality food-animal production rye, and timothy. Heat and colddensity, increase sustainability and actually may be harming our horses.Continued on page 8OCollege of Veterinary Medicine University of MissouriPage 7

Grazingcontinued from page 7stress, along with drought conditionswill change the composition of thegrass rapidly and alter its sugar levels.When night temperatures drop below40 degrees, the plant stops growingand sugar levels rise. In effect, horsesgrazing pasture during the spring andfall when temperatures frequently oscillate are eating grass that varies insugar content not only from day today, but from day to night. This constant state of flux can be problematicfor horses suffering from laminitis.The production of sugar is directlycorrelated with light intensity and duration. The content of the sugars foundin grass will be at its lowest betweenthe hours of 3 to 10 a.m. when temperatures at night are above 40 degrees.Sugar levels rise when the sun comesup and peak in the mid afternoon.Along with this, drought stress results in an accumulation of simplesugars in the grass. Grass that is justabout to go to seed, or has just goneto seed has the highest content ofPreventativeCareVaccinations andDentistryin simple sugars and somewhat lesspalatable. Some practical tips to safegrazing that can be helpful to you andyour horse include rotational grazing,restricted grazing, restricted grazingduring times of highest stress andoptimizing fertility and soil pH. Restricted grazing can be accomplishedin two ways: You can put your horsein a dry lot for part of the day, or agrazing muzzle can be applied.Horses that are at risk for laminitisshould be kept off of grass altogetherduring the periods when the nightsare below 40 degrees and the NSClevels are so variable. This period typically lasts six weeks in the spring andsix weeks in the fall. Allowing horsesto graze during the overnight periodand pulling them off of pasture duringpeak NSC times can also be useful. Fisimple sugars throughout the seed,nally, soil should be analyzed and ferleaf and stem.tilized accordingly. Nutrient deficiencies that retard growth tend to increaseWhen trying to determine a safe andthe NCS concentration of grasses.effective grazing scheme for horses affected by EMS, obesity or laminitis,For more tips on how to safely grazeit may not be practical to tear out all horses affected by EMS or laminitis,of your pastures and replant with na- please feel free to call and talk withtive species, which are typically lower one of our doctors.Remember, in addition to routine vac-cinations, brood mares require a rhinopneumonitis booster during their fifth,seventh, and ninth month of gestation inorder to help prevent abortions and weakfoals. It is also important to administer allrecommended vaccines one month priorto the mare’s expected foaling date in order to increase antibody content of themare’s colostrum. If you have any questions regarding vaccinations, please call usand we can discuss a vaccination schedulethat fits your horse’s needs.speculum and power equipment allow usto address the common dental issues, suchas sharp enamel points, as well as providethe ability to deal with more significantproblems on the farm. A thorough dentalQuality dental care is critical to the examination and annual float is critical towelfare of your horse. We recommend a the health and well-being of patients, andyearly dental examination. Our full mouth we are committed to providing that care.Equine Ambulatory News Fall 2008Page 8

New Facility Proposed toExpand Teaching, ServicesMissouri hasthe third largestequine population in the United States and theMU College ofVeterinary Medicine has a rich tradition in educatingstudents and veterinarians in the artand science of equine practice! Educating the next generation of veterinarians is an exciting challenge for allof us.Establishment of the Equine Teaching Center will be an important milestone in ensuring that we are able toprovide the very best experiences forour students, and will serve to improve Missouri’s equine herd health.Dr. Neil C. OlsonDean, College of Veterinary MedicineTeachingAs the only institution in the stateconferring a DVM, the College ofVeterinary Medicine at the Universityof Missouri graduates approximately75 students each year. Many of thesestudents go on to careers that includea presence in equine practice. Thecenter will offer the following: Space and facilities to enhancestudent instruction of practicalclinical skills; Proximate housing for horsesused for teaching on campus; Dedicated space for horse ownersand veterinary extension seminars, wetlabs and workshops; Facilities for whole animal teaching including palpation stocks,open areas and stables; Adequate space for equine theriogenology teaching.Service The Equine Teaching Center willnot only meet the need for state-ofthe-art educational facilities, it willalso provide improved options forequine care, treatment and services: Affordable horse stabling for healthy client breeding horses;Space to develop reproduction services, including semen collection;Affordable accommodations forclient-owned horses with con- ditions necessitating prolongedconvalescence.Other BenefitsThe Equine Teaching Center willoffer additional advantages to students and horse owners:College of Veterinary Medicine Accommodations for equine research projects and housing forhorses on campus within easy access of diagnostic modalities available in the Veterinary MedicalTeaching Hospital and VeterinaryMedical Diagnostic Laboratory;Turn-out paddocks for exercise ofteaching, research, and theriogenology horses, plus client-ownedhorses with conditions necessitating prolonged convalescence;Facilities readily serviced byVMTH staff and students,such as feeding, cleaning of stables, turn-out and night visits;Teaching and research horses separated from hospitalized, potentially disease-bearing animals forimproved biosecurity.University of MissouriPage 9

OvercomingBreedingIssuesExaminationCan ExposeFactors PreventingConceptionIt seems like such a natural thing – horsesFor a mare that enters the breeding season “barren,” i.e., the mare was bred durmate, the mare conceives, and then 340 ing the previous season but failed to delivdays later a foal is on the ground. Yet so er a foal at term, a comprehensive breedingmany times we find ourselves at the end of soundness exam is indicated to determinethe breeding season with a mare that is not the likelihood that the mare will conceive,pregnant. While infertility and early em- carry and deliver a live foal at term. Thebryonic loss are real problems in a relative- breeding soundness examination consistsly small population of mares, many cases of visual evaluation of the mare’s perinealof perceived infertility may be addressed conformation and mammary glands, exthrough simple and economic modifica- amination of the ovaries and reproductivetions in breeding management.tract by transrectal ultrasonography, examWhen planning a breeding, you should ination of the vagina and cervix, a uterineconsider the reproductive soundness of culture, and an endometrial biopsy.both the mare and stallion. While a comIf abnormalities are detected during thisprehensive breeding soundness examina- examination, additional diagnostics maytion on the stallion of interest is not prac- be pursued to evaluate your mare for suchtical in many situations, a pre-breeding problems as hormonal aberrations andsemen evaluation is desirable. If the mare structural abnormalities. Problems thatis to be bred to a non-local stallion using your veterinarian might identify on yourcooled, transported or frozen-thawed se- mare’s breeding soundness examinationmen, efforts should be made to discuss include poor conformation, cervical adhethe stallion’s semen quality and pregnancy sions, endometrial cysts, and ovarian abrates during prior seasons with the stal- normalities such as a granulosa cell tumor.lion’s owner, manager, or veterinarian priorContinued on page 11to committing to a breeding contract.Equine Ambulatory News Fall 2008Page 10

Fertilitycontinued from page 10If failure to conceive is a problemfor your mare, the first thing to consider is the quality of heat detection.Although certain mares show heatreadily there are others that will notobviously show heat unless they arepresented to a stallion. If you don’thave a stallion on your property to“tease” your mare, it would be bestto have your veterinarian perform atransrectal ultrasound examinationto assess where your mare is in hercycle. Your veterinarian can also administer medications to manipulatethe mare’s cycle and better plan whenshe will come into heat and be readyfor breeding.Another factor to consider whenbreeding your mare is day-to-daycare. If the plane of nutrition is inadequate and the horse is in poor bodycondition, the mare may experienceabnormalities of cyclicty, aspirate airand bacteria into the uterus, or poolurine near the cervical opening, allof which contribute to poor conception rates and early embryonic loss.Grossly overweight animals may alsosuffer from subfertility. Additionally,mares maintained in a stressful environment may fail to conceive or maylose an early embryo.In older (late teenage) mares, if nosignificant abnormalities are notedduring the breeding soundess examination and heat detection is optimal,you should consider normal age-related changes. Older mares, particularlymares that have not carried a foal, canhave endometrial fibrosis, or scar tissue, present that makes it difficult forthem to maintain a pregnancy. TheMaresmaintainedin a stressfulenvironmentmay fail toconceive ormay lose anearly embryo.ian during the breeding process andhave your mare examined by ultrasound early, as early as 14 days andno later than 16 days, to determinepregnancy. This will enable yourveterinarian to best deal with a twinpregnancy, if present. Additionally,your veterinarian can recommendnutrition and physical care, includingvaccination against equine herpes virus-1 at five, seven, and nine monthsOther abnormalities of reproducgestation; elimination of fescue fromtive that older mares can demonstratethe mare’s diet approximately twoare irregular cycles, sub-optimal oomonths before foaling; and routinecyte (egg) quality, and a predisposivaccinations at approximately onetion to uterine infection (pyometra).month prior to foaling. FollowingOverall, the best thing you can do these recommendations will increasewhen breeding your mare is to have the likelihood that you are welcoma good relationship with your veteri- ing a new addition to your farm thenarian. Consult with your veterinar- following season.presence and degree of endometrialfibrosis can be assessed by obtaining abiopsy. This information may then beused to help establish the probabilitythat the mare will be

private equine ambulatory practitioner. Dr. Loni Taylor grew up in Hope, Ark., competing in local 4-H, NBHA, and Arkansas Horse Show Association shows. Dr. Alison LaCarrubba, originally from New York, graduated from the University of Missouri College of Veterinary Medicine in 2001. Alison stayed on at MU to complete an internship in