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December 20202020 CENTER FOR EQUINE HEALTHRESEARCH REVIEWNew Discoveries in Equine Health
Table of Contents2020 CENTER FOR EQUINE HEALTHRESEARCH REVIEWDirector’s Message. 3Center for Equine Health Scientific Advisory Board. 4New Discoveries in Equine Health – December 2020Center for Equine Health Awards. 5Center for Equine HealthSchool of Veterinary MedicineUniversity of CaliforniaOne Shields AvenueDavis, California 95616-8589Telephone: 530-752-6433Fax: .com/ucdavis.cehwww.instagram.com/ucdavis cehResource Funds.7Published by the Center for Equine HealthMichael D. Lairmore, DVM, Ph.D., Dean, School ofVeterinary MedicineCarrie J. Finno, DVM, Ph.D., DACVIM, Director, Centerfor Equine HealthTom Hinds, Director Communications and Marketing,School of Veterinary MedicineAmy Young, Communications Specialist, Centerfor Equine HealthKaylie Kingston, Administrative Officer, Centerfor Equine HealthTatiana Viau, DVM, Animal Resource Manager,Center for Equine HealthThe Center for Equine Health is partially supported with funds provided by the Stateof California Pari-Mutuel Fund and contributions by private donors.The University of California does not discriminate in any of its policies, procedures,or practices. The University is an affirmative action/equal opportunity employer.The donor information you provide will be used for University business and will notbe released unless required by law. To review your record, contact AdvancementServices, 202 Cousteau Place, Suite 185, Davis, CA 95618. A portion of all gifts isused to defray the costs of administering the funds. All gifts are tax-deductible asprescribed by law.Innovation Funds.7Completed Research Studies. 9Resident Grants.30Partnerships Lead to Innovation in Veterinary Care. 37Publications.38Newly Funded Research Studies.42Center for Equine Health Researchers.44Center for Equine Health Donor Honor Roll.54Equine Tribute and Memorial Fund Supporters.56Equine PET: A Game Changer.58On the cover:Cover artwork by Carl Nelson Gorman from 1960, gifted in memoryof Shirley and Norman Carroll O’Connor to the UC Davis Museumthat bears his name.The C.N. Gorman Museum, currently located on the UC Daviscampus in Hart Hall, was founded in 1973 and is dedicated to theexhibition and engagement with contemporary Native Americanand Indigenous art. For almost half a century the C. N. GormanMuseum’s reputation of artistic excellence has been proven by itscompany of exhibiting artists, both established and emerging, anddedication to cultural diversity.
Director’s MessageGreetings!It is with great excitement that I welcome you to the 2020 Research Review, focused on the research accomplishments of UC Davis faculty,residents, students and staff as supported by the Center for Equine Health (CEH). The Center’s mission is to support equine teaching, researchand service activities essential to the UC Davis School of Veterinary Medicine. Our researchers have addressed challenging questions inefforts to advance equine health and welfare. This Review is a summary of these findings, translating our research discoveries directly to horseowners and veterinarians.Among these findings, UC Davis researchers have made significant strides in injury prevention in racehorses. Dr. Susan Stover and colleaguesat the J.D. Wheat Orthopedic Laboratory presented results on racetrack surface properties and the role of proximal sesamoid bone fracturesin catastrophic breakdowns in racing Thoroughbreds. Dr. Mathieu Spriet and collaborators pioneered the first equine positron emissiontomography (PET) scan and showed that the technology can successfully detect injuries at the molecular level. This diagnostic modality iscurrently being used in our southern California racetracks to PREVENT racehorse injuries.This Review also highlights the outstanding research performed by UC Davis veterinary residents. Resident and graduate training are toppriorities for CEH in order to train the next generation of equine clinician scientists. The CEH grant program provides residentswith firsthand experiences conducting research projects, from writing grants to generating results, and analyzing andpublishing their findings. We are proud to share the outcomes of resident research projects and are confidentthat these young professionals will make important contributions to veterinary medicine as they progress intheir careers.In addition to providing research funding through our competitive grant program, CEH managesa teaching herd of horses that are at the heart of our efforts. The discoveries presented in thefollowing pages would not be possible without our equine partners. We recognize the vitalroles that these exceptional equines play and celebrate their contributions to improvinghealth for all horses.Our research is supported by the generosity of the many donors who continue to makethe Center’s research program a success. Thank you to each and every donor for yourinvestment in CEH for the health and well-being of horses.Carrie J. Finno, DVM, Ph.D., DACVIMDirector, Center for Equine HealthNEW DISCOVERIES IN EQUINE HEALTH RESEARCH REVIEW 2020 3
CENTER FOR EQUINE HEALTH SCIENTIFIC ADVISORY BOARDVerena Affolter, DVM, Ph.D., DECVPProfessor, VM: Pathology, Microbiology, andImmunologyJeff Blea, DVM, Equine VeterinarianC. Titus Brown, Ph.D., Associate Professor,VM: Population Health and ReproductionDerek Cissell, VMD, Ph.D., DACVR, AssistantProfessor, VM: Surgical and Radiological SciencesAlan Conley, BVSC, Ph.D., FRCVS Professor,VM: Population Health and ReproductionJoseph Dowd, DVM, Ph.D., Equine VeterinarianGregory Ferraro, DVM, Director Emeritus, Centerfor Equine HealthCarrie Finno, DVM, Ph.D., DACVIM, Director,Center for Equine Health, Associate Professor,VM: Population Health and ReproductionKatherine Flynn, BVMS, MRCVS, CaliforniaDepartment of Food and AgricultureLarry Galuppo, DVM, DACVS, Professor,VM: Surgical and Radiological SciencesScott Katzman, DVM, DACVS-LA, AssistantProfessor, VM: Surgical and Radiological SciencesHeather Knych, DVM, Ph.D., DACVP, Professor,Kenneth L. Maddy Equine Analytical ChemistryLaboratoryIsaac Pessah, Ph.D., Associate Dean of Researchand Graduate Education, Professor, VM: MolecularBiosciencesNicola Pusterla, DVM, Ph.D., DACVIM, Professor,VM: Medicine and EpidemiologyClaudia Sonder, DVM, Director Emeritus, Center forEquine HealthIrwin Liu, DVM, MPVM, Ph.D., Professor Emeritus,VM: Population Health and ReproductionJoshua Stern, DVM, Ph.D., DACVIM, AssociateProfessor, VM: Medicine and EpidemiologyK. Gary Magdesian, DVM, DACVIM, DACVECC,DACVCP, CVA, Roberta A. and Carla HenryEndowed Chair in Emergency and Critical CareMedicine, VM: Medicine and EpidemiologySusan Stover, DVM, Ph.D., DACVS, Professor,VM: Surgical and Radiological SciencesStuart Meyers, DVM, Ph.D., Professor,VM: Anatomy, Physiology and Cell BiologyBrian Murphy, DVM, Ph.D., DACVP, AssociateProfessor, VM: Pathology, Microbiology, andImmunology4 UC DAVIS SCHOOL OF VETERINARY MEDICINE CENTER FOR EQUINE HEALTHFern Tablin, VMD, Ph.D., Professor Emeritus,VM: Anatomy, Physiology and Cell BiologyJoie Watson, DVM, Ph.D., DACVIM, AssociateDean and Professor, VM: Medicine andEpidemiologyErik Wisner, DVM, DACVR, Professor Emeritus,VM: Surgical and Radiological Sciences
CENTER FOR EQUINE HEALTH AWARDS2018 James M. Wilson Award –Jennifer Symons, PhDDr. Jennifer Symons received the 2018James M. Wilson Award in recognition ofher contributions to equine research. As amechanical and biomedical engineer, shecollaborated with Dr. Sue Stover and otherresearchers on the study “Modelling theeffect of race surface and racehorse limbparameters on in silico fetlock motion andpropensity for injury.”The aim of this study was to consider the effect of changing factors on fetlockmotion during gallop, and to determine which factors produce the greatestchanges. Dr. Symons and her colleagues tested this using a computer model of avirtual racehorse galloping on a virtual race surface. Study results indicate thatthe depth of the upper, softer layer of the race surface has the greatest potentialto influence fetlock flexion. Increasing the depth of this layer within the modeldecreased the degree of simulated fetlock flexion during gallop. Practically, thisparameter is related to race surface maintenance, specifically depth of harrowing.Other parameters that produced lesser changes in fetlock motion included lowerlayer race surface mechanics and racehorse tendon/ligament stiffness. ChangesJames M. Wilson AwardThe James M. Wilson Award is given each year to an outstandingequine research publication authored by a graduate student orresident in the UC Davis School of Veterinary Medicine. The Centerfor Equine Health Scientific Advisory Board judges the papersbased on scientific merit, quality of writing and relevance to theequine industry. Dr. Wilson was a 1945 graduate of the Ohio StateUniversity College of Veterinary Medicine. He was a well-knownand respected racetrack veterinarian in California and maintained astrong interest in equine research at UC Davis.in friction between the hoof and race surface produced the smallest changes infetlock motion.These computer model results provide evidence to guide race surfacemanagement decisions to reduce the incidence of fetlock injuries in racehorses,particularly through the depth of harrowing race surfaces.2019 James M. Wilson Award –Regina Zavodovskaya, DVMDr. Regina Zavodovskaya received the2019 James M. Wilson Award for her researchpublication describing signals of bone productionin horses with silicate-associated osteoporosis.Dr. Zavodovskaya is a board -certified veterinarypathologist pursuing a PhD in the IntegrativePathobiology Graduate Group under thementorship of Dr. Susan Stover.Osteoporosis is a debilitating disease in whichbones are weakened and prone to disfigurementsand fractures. Horses with fragile bones havebeen identified in regions of California withsoils rich in naturally occurring toxic silicate crystals. These horses also sufferfrom a lung disease called silicosis as a result of breathing dust containing thecrystals. Concurrent osteoporosis and silicosis is named silicate-associatedosteoporosis (SAO).Since there are currently no markers for diagnostic testing, Dr. Zavodovskayainvestigated the mechanism of bone loss by comparing tissue signal profilesin bones of horses with and without SAO. Computer programs assessed thesignal patterns and constructed signal profiles differentiating SAO-affected andnormal horses. The study results showed an unexpected pattern of increasedbone production in SAO horses compared to the normal group. It is possible thataffected horses produced more bone as compensation for the excessive bonedestruction that they experienced.These results provide signals specific to SAO that can be developed into amuch-needed tool to detect affected horses early and slow the progression ofSAO through appropriate treatment.NEW DISCOVERIES IN EQUINE HEALTH RESEARCH REVIEW 2020 5
CENTER FOR EQUINE HEALTH AWARDSLouis R. RowanFellowshipThe Louis R. RowanFellowship, funded by theCalifornia ThoroughbredFoundation with financialassistance from the OakTree Racing Association,was established inmemory of one of theCalifornia ThoroughbredFoundation’s founders.In addition to being anoted racehorse ownerand breeder, Rowenwas active in manyareas that benefitedpeople and horses in theThoroughbred world.2018 Rowan Fellowship – Monica Pechanec2019 Rowan Fellowship – Sarah ShafferMonica Pechanec wasselected to receive the2018 Louis R. RowanFellowship. She is a Ph.D.student in the AnimalBiology Graduate Groupconducting researchon equine tendonregeneration under theguidance of Dr. MichaelMienaltowski. She iscombining the fields ofanatomy, engineering,biochemistry, andmolecular biology as sheresearches tendon formation in horses. The goal is to developinsights and strategies for equine tendon repair.She did her undergraduate work at Brown University andearned her M.S. in animal biology at UC Davis. In additionto her research work, she has served as a teaching assistantat UC Davis.Outside her university pursuits, she is a horse enthusiastand athlete. Since relocating to Davis, she acquired a racingArabian, which she trains for long trail rides and possibleendurance riding. She was a childhood gymnast and competedin pole vault at Brown.Sarah Shaffer, a Ph.D.candidate in mechanicalengineering, was awardedthe 2019 Louis R. RowanFellowship. Shafferconducts research onracehorse fractures atthe J.D. Wheat VeterinaryOrthopedics ResearchLaboratory under thedirection of Dr. SusanStover.Fractures of the proximal sesamoid bones, which arelocated in a horse’s ankles, are among the most commonfatal bone fractures in Thoroughbred racehorses. The goalof Shaffer’s work is to create a mathematical model of theproximal sesamoid bones that will predict fracture riskbased on the training program. Ideally, results could providerecommendations to owners, trainers, and veterinarians asto which training programs put horses at a higher or lowerfracture risk.A lifelong equestrian, Shaffer holds a National ReiningHorse Association Youth World Title and multiple top tenplacings at the American Quarter Horse Congress in reiningwith her Quarter Horse, Roostamatic (a.k.a. Beau). Aftercompleting her Ph.D., Shaffer intends to work in the equinebiomechanics field as a professor at a research institution.6 UC DAVIS SCHOOL OF VETERINARY MEDICINE CENTER FOR EQUINE HEALTH
RESOURCE FUNDSINNOVATION FUNDSCenter for Equine Health Directorship SupportFund – This fund was established by the estate ofJoyce E. Williams in 2015 to provide support funds tothe CEH director.Animal Rescue and Disaster MedicineEndowment – The Animal Rescue and DisasterMedicine Endowment supports the development ofimproved techniques for the rescue of large animalsduring natural disasters. The fund also providesfor research into various medical conditions of theanimals and the development of improved treatmentregimens.Director’s Endowment – The Director’sEndowment provides general funding for Centerfor Equine Health research, educational or welfareactivities most critical to the needs of the horse inany given year. This endowment also provides thefoundation for all Center endeavors.Gregory L. Ferraro Endowed Directorship –This endowment was established in 2015 in honorof Dr. Gregory L. Ferraro, director emeritus of theCenter for Equine Health, for his lifelong dedicationto advancing the health and welfare of horses. Thefund provides support to the director to developthe vision and plan for the enduring success ofthe Center.Bernard and Gloria Sallck Equine Viral DiseaseLaboratory Endowment – This endowmentsupports a program dedicated to internationalscientific investigations of emerging equine viraldiseases. Its goal is to identify and control viraldiseases of the horse that can affect the internationalmovement, commerce and health of competitiveequine athletes.Polly and Bill Swinerton Director’s Endowment– This fund supports the activities of the Centerfor Equine Health Director to advance the facility’steaching, research and service missions.Dan Evans Memorial Endowment – The DanEvans Memorial Endowment provides funding forUC Davis Veterinary Medical Teaching Hospitalresident house officers to conduct research inany area of equine medicine and surgery that isrelevant to the development of their specialty boardcertification.William and Inez Mable Family FoundationEndowment – This endowed fund was establishedto support the Center for Equine Health in itsoperational, educational and research efforts.Endowment earnings are distributed at the directionof the Center Director for advancing the health, wellbeing, performance, and veterinary care of horsesthrough research and/or education.Enduring Legacy Endowment – The EnduringLegacy Endowment was established to providefor the administration of experimental or highrisk therapies to severely ill or injured horses withunique veterinary conditions for which there is ahigh degree of learning value associated with theircondition. The fund also supports the clinical trialsprogram within the School of Veterinary Medicine.Equine Athletic Performance LaboratoryEndowment – The Equine Athletic PerformanceLaboratory Endowment provides for thedevelopment of analytical methods for accuratelyevaluating the athletic conditioning andperformance capability of individual horses. Oncethese analytical techniques are fully developed,the goal of the program is to provide an objectiveevaluation of the ability of drug agents and trainingmethods to enhance performance and decrease therisk of injury in competitive horses.James M. Wilson Endowment – Establishedin 1995 to honor Dr. James M. Wilson, thefund supports an annual award recognizing anoutstanding resident or graduate student researcher.J.D. Wheat Veterinary Orthopedic ResearchLaboratory Endowment – The J.D. WheatVeterinary Orthopedic Research Laboratoryinvestigates the underlying causes of bone fractures,their prevention, and new methods of fracturerepair. This Laboratory was originally establishedby the Southern California Equine Foundation, Inc.,with funds provided by the Dolly Green ResearchFoundation.John P. Hughes Memorial Endowment – Namedafter the founding director of the Center for EquineHealth, the John P. Hughes Memorial Endowmentprovides funding for UC Davis Veterinary MedicalTeaching Hospital resident house officers to conductclinical research in any area of equine medicineor surgery.NEW DISCOVERIES IN EQUINE HEALTH RESEARCH REVIEW 2020 7
INNOVATION FUNDS continuedJuliette Weston Suhr Fellowship Fund – TheJuliette Weston Suhr Fellowship is awarded topostgraduate veterinary students who are interestedin conducting research in the areas of exerciserelated cardiopulmonary and metabolic disorders.Patricia J Hobbs Endowed Research –Established by the estate of Patricia J Hobbs in2009 to support research in the field of equinelaminitis.Lorna Talbot Equine Biomedical Fund –Established by Lorna Talbot in 2003, the fundpromotes the development of new and re-emergingresearch programs in basic equine sciences.Patricia Yeretzian Endowment Fund – Thisfund was established by longtime Silver StirrupSociety members, Patricia and Paul Yeretzian.The fund supports equine research projectsrelating to reproduction and infertility disorders.Lorna Talbot Equine Clinical Program –Established by Lorna Talbot in 2003, the fundpromotes the development of new medical programsof clinical relevance with the Veterinary MedicalTeaching Hospital.Peray Memorial Endowment – The PerayMemorial Endowment is an important resourcefor resident house officers of the UC DavisVeterinary Medical Teaching Hospital to conductequine respiratory disease and colic research.Lucy G. Whittier Endowment for EquinePerinatal and Infectious Disease – The Lucy G.Whittier Endowment is dedicated to improving thehealth and medical treatment of newborn foals andtheir dams and to conduct researchon infectious diseasesassociated with foals.Performance Horse Endowment – Medicalproblems of the mature show and eventhorse are the focus of the Performance HorseEndowment. This endowment also fundslong-term, in-depth studies of problems thatpreclude horses from performing athleticallyas they age. Areas of study include colic,nutrition, cardiopulmonary health, degenerativeorthopedic processes and infectiousdisease.Sundance Ranch Endowment – Thisfund was established by the late Carol Greento provide funding support for research inbiological and translational research in thepursuit of effective treatments and cures forsystemic diseases of the horse. Ms. Green hadparticular interest in medical conditions relatedto the development of laminitis.8 UC DAVIS SCHOOL OF VETERINARY MEDICINE CENTER FOR EQUINE HEALTHSimulcast RacingContributionsIn 1987, the Satellite Wagering Act (SenateBill 14) designated one-tenth of one percentof California’s simulcast racing handleto be used for equine research. In 1994,Senate Bill 518 was passed, designatingthe redistribution of the simulcast racingpercentage. These funds support both theCenter for Equine Health and the KennethL. Maddy Equine Analytical ChemistryLaboratory. This important laboratory hasthree components: (1) a full-service, routinedrug testing program, (2) a forensic toxicologyprogram, and (3) a pharmacology researchand methods development program. Thelatter includes the development of new testsand documentation of drug testing effectson racehorse performance. In 2001, theAccount Wagering Bill (Assembly Bill 471)was passed, directing simulcast contributionsmade through televised wagering to UC Davisequine research and drug testing programs.
COMPLETED RESEARCH STUDIESDRUG THERAPIESGENETICSInvestigation of vitamin E metabolism in horsesand the effect of supplementation (Grant #16-14)Investigating a genetic riskfactor for eye and skin cancerin horses (Grant #16-06)Investigators: Birgit Puschner, DVM, PhD, DABVT, Carrie J. Finno, DVM, PhD,DACVIM, Xiaopeng Chen, PhDVitamin E (vitE) is one of the most important fat-soluble vitamins and horsesobtain most of their vitE from fresh pasture. Understanding the metabolicpathways of vitE is essential to define optimal dietary vitE intake in horses.Additionally, the cause for equine neuroaxonal dystrophy (eNAD) remainsunknown but may be due to altered vitE metabolism. We were able to developreliable assays to detect concentrations of vitE isoforms (α-tocopherol,γ-tocopherol, α-tocotrienol, γ-tocotrienol) and metabolites (α –CMBHC,α –CEHC and γ-CEHC) in serum and urine from healthy horses with adequateaccess to fresh pasture. Once we established reference ranges, we assayedthem in a group of healthy horses and eNAD-affected horses before and afteradministration of 5000 IU of α-tocopherol orally. We found that horses witheNAD metabolized α-tocopherol more rapidly than unaffectedhorses. These results support the current hypothesis that theetiology of eNAD involves a genetic defect leading to abnormalmetabolism of vitamin E.How does this research benefit horses? We havedeveloped an assay to measure concentrations of vitEisoforms and metabolites in equine serum and urinesamples. Preliminary results from this study indicate thatthis could potentially serve as an antemortem diagnostictest for eNAD; however, we will first validate these findings in alarger study population.This research is in press with the Journal of Veterinary Diagnostic Investigation.Investigators: Rebecca R. Bellone PhD, Mary LassalineDVM, PhD, DACVO, Christopher M Reilly MAS, DVM,DACVP, Tammy Miller Michau DVM, MS, MSpVM, DACVO, JiayinLiu, Savanna Vig DVM, Moriel Singer-Berk BSSquamous cell carcinoma (SCC) is the most common cancer of eyes and thesecond most common tumor of the horse overall. A change in the DNA that alsoleads to a change in the gene product (missense mutation) in damage-specificDNA-binding protein 2 (DDB2, c.1012 C T, p.Thr338Met) was previously foundto be strongly associated with SCC in Haflingers. This study determined thatthis same mutation explains 76% of all ocular cases of the Haflinger and Belgianbreeds. This variant also explained ocular SCC in the only reported case fromthe Rocky Mountain Horse breed. This variant was not associated with ocularSCC in the Arabian, Appaloosa, or Percheron breeds, or with oral or urogenitalSCC of any breed investigated (P 0.05). Finally, functional analysis usingrecombinant DDB2 protein further supports that this variant (p.Thr338Met) isa causal genetic risk factor, as the protein with methionine at amino acid 338 isunable to bind to UV damaged DNA.How does this research benefit horses? This study confirmed that theDDB2 mutation is a risk factor specifically for ocular SCC in multiple breeds ofhorses (Haflinger, Belgian, and Rocky Mountain Horses, but not Appaloosa andArabian). This further supports the use of this mutation as a breed specific DNAtest to inform mating decisions and management practices, thus lowering theincidence of the disease, enabling earlier detection and better prognosis.This research was reported in Animal Genetics 2018 Oct; 49(5):457-460,Veterinary Ophthalmology 2019 Mar; 22(2):201-205, the International Journalof Genomics 2019 Sept; 3610965, and the Equine Veterinary Journal 2020 Jan;52(1):34-40.To obtain additional information on a research study, please reference the grant number in your request.NEW DISCOVERIES IN EQUINE HEALTH RESEARCH REVIEW 2020 9
COMPLETED RESEARCH STUDIES continuedInvestigating genetic risk loci for ocular squamouscell carcinoma in horses (Grant #17-12)Investigators: Rebecca R. Bellone,PhD, Mary E. Lassaline, DVM, PhD,Kelly E. Kniceklbein, VMDSquamous cell carcinoma (SCC) is themost common cancer of the equineeye and the second most commontumor of the horse overall. SCCfrequently originates on the thirdeyelid or the limbus (where the clearcornea meets the white sclera) andcan grow quickly to invade the eye andadjacent structures, leading to visionloss and destruction of the eye. Amutation in a DNA ultraviolet radiationDrs. Mary Lassaline and Kelly Knickelbeinrepair enzyme (DDB2) was previouslyexamining a Haflinger horse to enroll in theocular SCC study.identified as associated with increasedrisk for ocular SCC development in theHaflinger and Belgian breeds, thoughnot all affected horses could be explained by this mutation. The objective of thisstudy was to identify additional DNA mutations for association with ocular SCCin Haflinger and Belgian horses. Investigating the previously associated locusdid not identify another variant more strongly associated with ocular SCC inHaflingers or Belgians than the one identified previously in DDB2. When takingthe DDB2 risk variant genotype into account, statistical analysis supported avariant located on horse chromosome 6 as a second risk factor for ocular SCCin both Belgian and Haflinger horses (P 2.75 X10-4). This variant is a missensevariant in a gene involved in the same UV damage DNA repair process as DDB2.How does this research benefit horses? This work has advanced ourunderstanding of the genetic risk for ocular squamous cell carcinoma in horses.These data further support the use of genetic testing for the DDB2 variant inHaflinger and Belgian breeds. Testing for this variant can inform management andbreeding decisions. This study also identified an additional genetic risk factor that10 UC DAVIS SCHOOL OF VETERINARY MEDICINE CENTER FOR EQUINE HEALTHcould be utilized in DNA testingto develop the most robust ocularSCC risk assessment in these twobreeds. Functional studies are needed toconfirm the role of this variant in cancer.This research was reported in theInternational Journal of Genomics 2019 Sept;3610965.THE UC DAVIS VETERINARY GENETICS LABORATORY is nowoffering a genetic test for Ocular Squamous Cell Carcinoma (SCC) inHaflinger, Belgian and Rocky Mountain Horses. Testing for this riskvariant can help owners and breeders identify horses at higher risk andcan assist in mating pair selection. Homozygous horses (R/R) are advisedto have routine eye exams performed by a veterinary ophthalmologistfor early detection and better prognosis, and to wear a UV protecting flymask when out during the daylight hours. Breeding homozygotes (R/R)and heterozygous (R/N) should be avoided to reduce the chances ofproducing horses that have a high risk of developing this cancer.
Identification of the mutations resulting in bloodgroup A factors to prevent or plan for neonatalisoerythrolysis (Grant #16-12)Finding the genetic mutation for equineneuroaxonal dystrophy (Grant #17-02)Investigators: Robert A. Grahn, PhD, M. Cecilia Torres Penedo, PhDEquine neuroaxonal dystrophy (eNAD) is a devastating neurologicalcondition that develops during the first year of life in genetically predisposedfoals maintained on a vitamin E deficient diet. Affected horses suffer fromincoordination, preventing their use as riding animals. Our previous studyidentified possible genetic regions of interest associated with eNAD. We thenused whole-genome sequencing to find possible underlying mutations in theseregions in a small number of eNAD-affected and unaffected horses. This studysought to validate these potential mutations in additional horses, particularlyin the candidate gene, CYP4F2, which encodes the protein responsible formetabolizing vitamin E. Forty variants identified as possible candidates for eNADwere excluded. While no structural variants or segregating SNPs associated witheNAD/EDM were identified in CYP4F2, the gene demonstrated significantlyincreased expression ( 1.63x, P 0.02) in liver from eNAD-affected horses.How does this research benefit horses? We have identified increasedexpression of CYP4F2, which encodesthe major protein responsible forvitamin E metabolism in the liver, ineNAD-affected horses. In 2016, withCEH support, we had identified alteredmetabolism of α-tocopherol, the majorisoform of vita
Amy Young, Communications Specialist, Center for Equine Health Kaylie Kingston, Administrative Officer, Center for Equine Health Tatiana Viau, DVM, Animal Resource Manager, Center for Equine Health The Center for Equine Health is partially supported with funds provided by the State of California Pari-Mutuel Fund and contributions by private donors.
