PROGRESSIVE NEURONOPATHY IN 2 CAIRN TERRIER LITTER MATES

Clinical, histopathological, and EM findings are described for two Cai rn terrier litter mates, an IS-month-old male and an ii-month-old fema le,vith progressive neuronopathy. The initial clinical signs were char acterized by hind limb weakness and ataxia, which deteriorated with ex ercise. These signs progressed over several months to tetraparesis. Pa thological examination revealed extensive chromatolytic degeneration o f neurons and moderate secondary Wallerian-type degeneration in the sp inal cord and brain stem. Progressive neuronopathy can be differentiat ed clinically from globoid cell leukodystrophy, another progressive ne urological disorder in Cairn terriers, by the exercise-induced deterio ration of the neurological signs. Progressive neuronopathy occurs only in Cairn terriers and because of the similarity in age of onset and t he occurrence in one litter, an inherited disease is suspected.