Canine storage disease characterized by hereditary progressive neurogenic muscular atrophy: breeding experiments and clinical manifestation.

Progressive neurogenic muscular atrophy due to storage of a compound lipid in the lower motor neurons was diagnosed in 3 English Pointers that were littermates. Using 2 clinically normal littermates of these 3 affected dogs and 2 clinically normal dogs of the 2nd litter from the parents of the original 3 affected dogs as the initial breeding stock, a breeding experiment was performed, resulting in a breeding line of 26 dogs, 4 of which had the disease and 6 of which died before 3 months of age. Results indicated that the disease may have an autosomal recessive mode of inheritance. The clinical manifestation and electrophysiologic findings indicated lower motor neuron involvement in the affected dogs produced by breeding consistent with findings in the original 3 affected dogs. Upper motor neurons or the sensory system was not involved. The disease appeared to be distinct from other canine storage diseases previously reported.