Muscular dystrophy (MD)-an inherited, degenerative myopathy in humans, dogs, and cats-was diagnosed in a 2-year-old weimaraner. The form of MD was similar to Duchenne's MD found in boys in that both arise from a mutation in the gene for dystrophin, an essential protein in muscle cells. MD has been described in various dog breeds, including golden and Labrador retrievers, but has not been reported in weimaraners. It is usually identified in dogs before they reach 1 year of age, but it was not diagnosed in this patient until it was 2 years old. Despite its slower onset, the dog showed classic signs of dystrophin-deficient MD, such as regurgitation, exercise intolerance, dysphagia, and generalized muscle atrophy. The MD was also associated with a hiatal hernia, cryptorchidism, and agenesis of the right kidney. Muscles of the neck, infraspinatus, and tongue were hypertrophied. Serum creatinine kinase levels were more than 80 times the normal level, while alanine transaminase levels were 3 times normal. Diagnosis was made from muscle biopsies with immunohistochemical staining of dystrophin protein.

COMMENTARY: Discovery of a more slowly progressive form of dystrophin-deficient MD in this dog is significant for weimaraner breeders, and owners and researchers of MD in other dog breeds and in humans can probably benefit from learning about its pattern of inheritance, progression, and prognosis. Unfortunately, information about this dog's sire, dam, and littermates was unavailable. It's important that researchers further investigate dystrophin-deficient MD in weimaraners.

Dystrophin-deficient muscular dystrophy in a weimaraner. Baltzer WI, Calise DV, Levine JM, et al. JAAHA 43:227-232, 2007.