Hereditary spinal muscular atrophy in Brittany Spaniels: clinical manifestations.

A progressive neurologic disease was identified in a family of closely related Britanny Spaniel dogs. The disease developed in dogs less than 1 year old and characteristically resulted in paraspinal and proximal pelvic limb muscular atrophy. Neurologic examination, electrodiagnostic testing, and histologic studies indicated that the disease results from motor horn cell degeneration. A colony of affected dogs was established, and breeding studies incriminated an inherited basis for the disease.