CANINE EPILEPSY - A GENETIC-COUNSELING PROGRAM FOR KEESHONDS

The predisposition of keeshonds (Dutch barge dogs) to an idiopathic ep ilepsy appears to be determined by a single autosomal recessive gene. The pedigrees of 15 litters which included animals diagnosed as epilep tic ('fitters') were compared with those of 34 contemporary, normal an imals, The pedigrees of ail the fitters traced back, on both the pater nal and maternal sides, to a common ancestor. Subsequently, further pe digrees and details of litters were gathered, If both parents of a fit ter were heterozygous ('carriers'), the progeny (120 in number) of all known carrier x carrier matings would be expected to have a ratio of three phenotypically normal animals to one fitter, that is, 90:30. The ratio observed (91:29) was not significantly different, The Keeshond Club has published a list from which the identities of carriers can be inferred, with the intention that known carriers should be excluded f rom breeding, A genetic counselling programme has been in operation si nce 1989, which is based on advising breeders on the probability that the offspring of proposed matings would be fitters or carriers; advice has been given on 77 proposed matings. The mean probability that the proposed matings would result in carriers has declined significantly, and this is consistent with a decline in the frequency of the gene for this form of epilepsy in the breed.