• 1.

    Dacre KJP, Pirie S, Prince DP. Choke, pleuropneumonia and suspected gentamicin vestibulotoxicity in a horse. Equine Vet Educ 2003;15:2733.

    • Search Google Scholar
    • Export Citation
  • 2.

    Aleman M, Puchalski SM, Williams DC, et al.Brainstem auditory-evoked responses in horses with temporohyoid osteoarthropathy. J Vet Intern Med 2008;22:11961202.

    • Search Google Scholar
    • Export Citation
  • 3.

    Mayhew IG, Washbourne JR. A method of assessing auditory and brainstem function in horses. Br Vet J 1990;146:509518.

  • 4.

    Strain GM. Aetiology, prevalence and diagnosis of deafness in dogs and cats. Br Vet J 1996;152:1736.

  • 5.

    Geigy CA, Heid S, Steffen F, et al.Does a pleiotropic gene explain deafness and blue irises in white cats? Vet J 2007;173:548553.

  • 6.

    Strain GM. Deafness prevalence and pigmentation and gender associations in dog breeds at risk. Vet J 2004;167:2332.

  • 7.

    Matsushima Y, Shinkai Y, Kobayashi Y, et al.A mouse model of Waardenburg syndrome type 4 with a new spontaneous mutation of the endothelin-B receptor gene. Mamm Genome 2002;13:3035.

    • Search Google Scholar
    • Export Citation
  • 8.

    Steel KP, Barkway C. Another role for melanocytes: their importance for normal stria vascularis development in the mammalian inner ear. Development 1989;107:453463.

    • Search Google Scholar
    • Export Citation
  • 9.

    Price ER, Fisher DE. Sensorineural deafness and pigmentation genes: melanocytes and the Mitf Transcriptional Network. Neuron 2001;30:1518.

    • Search Google Scholar
    • Export Citation
  • 10.

    Harland MM, Stewart AJ, Marshall AE, et al.Diagnosis of deafness in a horse by brainstem auditory evoked potential. Can Vet J 2006;47:151154.

    • Search Google Scholar
    • Export Citation
  • 11.

    Sponenberg DP. Genetic equation, American Paint Horse Association. Available at: www.apha.com/breed/geneticeq.html. Accessed Oct 31, 2008.

    • Search Google Scholar
    • Export Citation
  • 12.

    Brooks SA, Lear TL, Adelson DL, et al.A chromosome inversion near the KIT gene and the Tobiano spotting pattern in horses. Cytogenet Genome Res 2007;119:225230.

    • Search Google Scholar
    • Export Citation
  • 13.

    Metallinos DL, Bowling AT, Rine J. A missense mutation in the endothelin-B receptor gene is associated with Lethal White Foal Syndrome: an equine version of Hirschsprung disease. Mamm Genome 1998;9:426431.

    • Search Google Scholar
    • Export Citation
  • 14.

    Brooks SA, Bailey E. Exon skipping in the KIT gene causes a Sabino spotting pattern in horses. Mamm Genome 2005;16:893902.

  • 15.

    Santschi EM, Vrotsos PD, Purdy AK, et al.Incidence of the endothelin receptor B mutation that causes lethal white foal syndrome in white-patterned horses. Am J Vet Res 2001;62:97103.

    • Search Google Scholar
    • Export Citation
  • 16.

    American Paint Horse Association Web site. APHA Plus, APHA online. Available at: www.APHAonline.com. Accessed Oct 31, 2008.

  • 17.

    Strain GM. Deafness in blue-eyed white cats: the uphill road to solving polygenic disorders. Vet J 2007;173:471472.

  • 18.

    Gauly M, Vaughan J, Hogreve SK. Brainstem auditory-evoked potential assessment of auditory function and congenital deafness in llamas (Lama glama) and alpacas (L pacos). J Vet Intern Med 2005;19:756760.

    • Search Google Scholar
    • Export Citation
  • 19.

    Leipold HW, Huston K. A herd of glass-eyed albino Hereford cattle. J Hered 1966;57:179182.

  • 20.

    Platt S, Freeman J, di Stefani A, et al.Prevalence of unilateral and bilateral deafness in border collies and association with phenotype. J Vet Intern Med 2006;20:13551362.

    • Search Google Scholar
    • Export Citation
  • 21.

    Cargill EJ, Famula TR, Strain GM, et al.Heritability and segregation analysis of deafness in US Dalmatians. Genetics 2004;166:13851393.

  • 22.

    Delack JB. Hereditary deafness in the white cat. Compend Contin Educ Pract Vet 1984;6:609619.

  • 23.

    Strain GM, Kearney MT, Gignac IJ, et al.Brainstem auditoryevoked potential assessment of congenital deafness in Dalmatians: associations with phenotypic markers. J Vet Intern Med 1992;6:175182.

    • Search Google Scholar
    • Export Citation
  • 24.

    Amiel J, Sproat-Emison E, Garcia-Barcelo M, et al.Hirschsprung disease, associated syndromes and genetics: a review. J Med Genet 2008;45:114.

    • Search Google Scholar
    • Export Citation
  • 25.

    Knox G, McPherson A, Lopes AM. Atypical presentation of Waardenburg's syndrome type II. Otolaryngol Head Neck Surg 1999;120:749.

  • 26.

    Tryon RC, Penedo MCT, McCue ME, et al.Evaluation of allele frequencies of inherited disease genes in subgroups of American Quarter Horses. J Am Vet Med Assoc 2009;234:120125.

    • Search Google Scholar
    • Export Citation

Advertisement

Evaluation of deafness in American Paint Horses by phenotype, brainstem auditory-evoked responses, and endothelin receptor B genotype

K. Gary Magdesian DVM, DACVIM, DACVCP, DACVECC1, D. Colette Williams BS2, Monica Aleman MVZ, PhD, DACVIM3, Richard A. LeCouteur BVSc, PhD, DACVIM4, and John E. Madigan DVM, MS, DACVIM5
View More View Less
  • 1 Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.
  • | 2 Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.
  • | 3 Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.
  • | 4 Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.
  • | 5 Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

Abstract

Objective—To evaluate deafness in American Paint Horses by phenotype, clinical findings, brainstem auditory-evoked responses (BAERs), and endothelin B receptor (EDNBR) genotype.

Design—Case series and case-control studies.

Animals—14 deaf American Paint Horses, 20 suspected-deaf American Paint Horses, and 13 nondeaf American Paint Horses and Pintos.

Procedures—Horses were categorized on the basis of coat color pattern and eye color. Testing for the EDNBR gene mutation (associated with overo lethal white foal syndrome) and BAERs was performed. Additional clinical findings were obtained from medical records.

Results—All 14 deaf horses had loss of all BAER waveforms consistent with complete deafness. Most horses had the splashed white or splashed white–frame blend coat pattern. Other patterns included frame overo and tovero. All of the deaf horses had extensive head and limb white markings, although the amount of white on the neck and trunk varied widely. All horses had at least 1 partially heterochromic iris, and most had 2 blue eyes. Ninety-one percent (31/34) of deaf and suspected-deaf horses had the EDNBR gene mutation. Deaf and suspected-deaf horses were used successfully for various performance events. All nondeaf horses had unremarkable BAER results.

Conclusions and Clinical Relevance—Veterinarians should be aware of deafness among American Paint Horses, particularly those with a splashed white or frame overo coat color pattern, blend of these patterns, or tovero pattern. Horses with extensive head and limb markings and those with blue eyes appeared to be at particular risk.

Contributor Notes

Presented in abstract form at the 16th Annual American College of Veterinary Internal Medicine Forum, San Diego, May 1998.

The authors thank Dr. A. T. Bowling for performance of genetic tests.

Address correspondence to Dr. Magdesian (kgmagdesian@vmth.ucdavis.edu).