Jump to content

Congenital sensorineural deafness in cats

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by 83.80.189.242 (talk) at 23:40, 3 December 2016 (Made adjustments to the claim that the condition is associated with blue irises, fixed it to include all iris colors and cited the reference.). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

A completely deaf, pure white, blue-eyed cat
Deaf, odd-eyed white cat.

Deaf white cats are domestic cats with a pure white coat. Some all-white cats suffer from congenital deafness caused by a degeneration of the inner ear.[1] This condition can occur in cats with yellow, green and blue irises, although the chances of deafness are dramatically increased with blue irises.[2] In white cats with mixed-coloured eyes (odd-eyed cats), it has been found that deafness is more likely to affect the ear on the blue-eyed side.[1] White cats can have blue, gold, green, or copper coloured odd eyes.

In one 1997 study of white cats with varying degrees of hearing deficiency, 72% of the animals[clarification needed] were found to be totally deaf. The entire organ of Corti was found to have degenerated within the first few weeks after birth; however, even during these weeks no brain stem responses could be evoked by auditory stimuli, suggesting that these animals had never experienced any auditory sensations. It was found that some months after the organ of Corti had degenerated, the spiral ganglion also began to degenerate.[3]

Genetics

The gene that causes a cat to have a white coat is a dominant masking gene. As a result, the cat will have an underlying coat colour and pattern. When the dominant white gene is present, however, that pattern will not be expressed. A cat that is homozygous (WW) or heterozygous (Ww) for this gene will have a white coat despite the underlying pattern/colour. A cat that lacks this dominant masking gene (ww) will exhibit a coat colour/pattern. There are several sources for a white cat to have blue eyes. If the underlying coat pattern is one of a pointed cat (also referred to as a Siamese pattern), the blue eyes may come from the genetics of the pointed gene. A common misconception is that all white cats with blue eyes are deaf.[4] It is possible to have a cat with a naturally white coat without this gene, as an extreme form of white spotting, although this is rare – some small non-white patch usually remains.

See also

References

Wikimedia Commons has media related to Deaf white cats.
  1. ^ a b Observations on the Histological Features, Development and Pathogenesis of the Inner Ear Degeneration of the Deaf White Cat
  2. ^ "Ask Elizabeth: White Cats and Blindness/Deafness". Cornell University College of Veterinary Medicine. Cornell University College of Veterinary Medicine Ithaca, New York. Retrieved 3 December 2016.
  3. ^ A model for prelingual deafness, the congenitally deaf white cat –population statistics and degenerative changes
  4. ^ George M. Strain (2011). Deafness in Dogs and Cats. CABI. pp. 68. ISBN 978-1-84593-764-5.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Congenital_sensorineural_deafness_in_cats&oldid=752886435"