LABRADOR RETRIEVER CENTRAL AXONOPATHY

Eleven Labrador Retriever puppies from a total of 36 puppies in four different litters were diagnosed with a diffuse central nervous system axonopathy. Clinical signs began with a pelvic limb gait disorder around the time the puppies first began to walk. Signs rapidly progressed to the throcic limbs. After progression for a number of weeks the signs became static. By then the dogs were unable to stand and walk without assistance. The gait disorder reflected a spinal cord and cerebellar dysfunction. At necropsy a diffuse symmetrical axonopathy predominated in the tracts in the dorsolateral funiculus and fasciculus gracilis with less pronounced lesions in the ventral funiculi. Axonopathy involved the Purkinje cells of some cerebellar folia and a neuronopathy occurred in the olivary nuclei. An autosomal recessive inheritance is suspected.