A spontaneously occurring myopathy that resembles in many ways muscular dystrophy in man has been observed in a strain of white Pekin ducks.1,2 Of these ducks, 10% developed contractures, usually between the 7th and 21st day of life, in one or both extremities.3 Many had muscular weakness and morphologic changes in the muscle without contractures. The histologic lesions in the striated muscle were characterized by focal areas of necrosis within individual muscle fibers.1-3 Genetic studies now in progress would suggest that transmittal does occur.
A variety of agents have produced degenerative lesions in the striated muscle of different laboratory animals: irradiation,4,5 a chemical,6 bacterial infections,7 viruses,8 vitamin deficiency,9 and massive doses of cortisone.10,11 A genetic disease has been described in which there are degenerative lesions in the striated muscle of the mouse,12 hamster,13,14 and chicken.15-17
Progressive muscular dystrophy