Disclaimer: These are from my notes and recollections and any mistakes contained are mine, not the speaker’s.
Congenital vs Late Onset (late onset does not occur in whippets)
Cochlear-saccular pathology – pigment related deafness
- deafness can be unilateral (one side) or bilateral (both sides)
- occurs at 3-4 weeks of age
- white pigment cells suppress melanocytes causing degradation of the hair cells
Neuroepithelial – usually occurs with ataxia, vestibular, head tremors, not pigment associated
Over 100 breeds are affected by pigment related deafness.
- recessive alleles of the piebald gene
- mode of inheritance is not Mendellian, possibly polygenetic or variable expression
Recessive alleles commonly associated with deafness
si – irish
sp – piebald
sw – extreme white
Merle locus – 2 dominat merle alleles
You can have a mostly solid colored dog who is bilaterally or unilaterally deaf, if they carry one of the recessives. If any of the litters parents or grandparents has one of the above genes, deafness is a possibility. You can not tell by looking at colors which puppies might be deaf!