Cat Breeds With Congenital Deafness

Very little information is available documenting deafness in various cat breeds. Deafness can result from effects of the dominant white (W) gene. A dominant piebald or white-spotting gene (S) is also found in various cat breeds (Pedersen, 1991; Searle, 1968), but there has been no report of deafness associated with its presence. Cats carrying the W gene are not always solid white, often having colored spots on their heads that may disappear with age. Unlike dogs with the merle gene, homozygous white cats do not have visual or reproductive defects, but they are more prone to the occurrence of blue irises and deafness, either unilateral or bilateral, and deafness occurrence increases with the number of blue eyes (Delack, 1984). Long-haired cats have a higher prevalence of blue eyes and deafness than short-haired cats (Mair, 1973). White cats carrying the underlying cs Siamese dilution pigment gene can have blue eyes without deafness, and it has been suggested that the presence of this gene explains why purebred white cats are less often deaf than mixed-breed white cats (Pedersen, 1991). Data supporting this is not available.

From studies of mixed-breed white cats (the W gene):

Out of 256 white cats from three studies (Bosher & Hallpike, 1965; Mair, 1973; Bergsma & Brown, 1971; reviewed by Delack, 1984), 12.1% were unilaterally deaf and 37.9% were bilaterally deaf, or a total of 50% were affected (Delack, 1984).

(Delack, 1984). When cats that were the offspring of two white parents were examined, the prevalence of deafness (unilateral or bilateral) ranged from 52% to 96%.

When Mair (1973) and Bergsma & Brown (1971) examined the effect of blue eye color on deafness, they found, respectively, a prevalence of deafness (unilateral and bilateral combined) of 85% and 64.9% in cats with two blue eyes, 40% and 39.1% in cats with one blue eye, and 16.7% and 22% in cats with no blue eyes.

Purebred white cats are said to have a lower prevalence of deafness than mixed-breed white cats (Pedersen, 1991), but supporting data are unavailable.

I am unaware of any study of deafness in cats by specific breed.

Pure cat breeds carrying the white (W) coat pigment gene (Gebhard et al., 1979) and at risk for congenital deafness (no prevalence data available):

White

White Scottish Fold

European White

Foreign White

Norwegian Forest Cats

Ragdoll

Siberian

White Turkish Angora

White American Wirehair

White Cornish Rex

White American Shorthair

White Devon Rex

White British Shorthair

White Manx

White Exotic Shorthair

White Persian

White Oriental Shorthair

White Maine Coon

It is obvious that much more research needs to be performed before deafness in cats is well understood. I would welcome further information from those who may be aware of resources I have not discovered. If you know of a cat breed with pigment-associated congenital deafness that is not listed here, please let me know at: strain@lsu.edu. Thanks.

References (see also Bibliography of Publications Related to Deafness in Cats):

Bergsma, D.R. & Brown, K.S. (1971). White fur, blue eyes, and deafness in the domestic cat. Journal of Heredity 62, 171-185.

62, 171-185. Bosher, S.K. & Hallpike, C.S. (1965). Observations of the histological features, development and pathogenesis of the inner ear degeneration of the deaf white cat. Proceedings of the Royal Society of London B 162, 147-170.

162, 147-170. Delack, J.B. (1984). Hereditary deafness in the white cat. Compendium on Continuing Education for the Practicing Veterinarian 6,609-619.

6,609-619. Gebhardt, R.H., Pond, G. & Raleigh, I. (1979). A Standard Guide to Cat Breeds . New York: McGraw-Hill Book Co.

. New York: McGraw-Hill Book Co. Mair, I.W.S. (1973). Hereditary deafness in the white cat. Acta Otolaryngologica Suppl 314,1-48.

314,1-48. Pedersen, N.C. (1991). Feline Husbandry . Goleta, CA: American Veterinary Publications.

. Goleta, CA: American Veterinary Publications. Searle, A.G. (1968). Comparative Genetics of Coat Colour in Mammals. London: Logos Press.

Dr. George M. Strain

Louisiana State University

Comparative Biomedical Sciences

School of Veterinary Medicine

Baton Rouge, Louisiana 70803

Phone: 225-578-9758

Fax: 225-578-9895

E-mail: strain@lsu.edu

November 5, 2009

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