Inheritance of a neuromuscular disorder of Labrador retriever dogs.

A heritable neuromuscular disorder of Labrador Retrievers was demonstrated to be transmitted by a simple autosomal recessive mode. The pathologic changes were confined to affected dogs, and a method for identifying the unaffected carrier was not found. The disorder was first recognized in 4 litters submitted for clinical examination, then was studied in 6 additional litters to determine the mode of inheritance. Although the disorder appeared widespread, its prevalence was thought to be low.