Clinical, radiographic, and pathologic abnormalities in dogs with multiple epiphyseal dysplasia: 19 cases (1991-2005).

Objective-To determine clinical, radiographic, and pathologic abnormalities in dogs with multiple epiphyseal dysplasia (MED). Design-Retrospective case series. Animals-19 dogs with MED from 10 litters. Procedures-The diagnosis was made on the basis of radiographs of the shoulder region and vertebral column. Ten dogs underwent necropsy. Results-There were 11 Hygenhund, 6 Dunker, 1 Golden Retriever, and 1 English Pointer. Most dogs were examined because of lameness that developed at 5 to 8 months of age. The most common radiographic abnormality was a deficiency in ossification of the epiphyses, apophyses, and cuboidal bones of the appendicular skeleton and the epiphyses of the vertebrae; ossification of the metaphyses and the diaphyses typically were normal. Disease severity was consistent among littermates, but varied among dogs from different litters. Conclusions and Clinical Relevance-Results suggested that MED is a rare condition in dogs characterized by a deficiency in ossification of the epiphyses of the long bones, the epiphyses of the vertebrae, the cuboidal bones, and the apophyses. Radiographic abnormalities were evident in dogs examined as young as 8 weeks of age, and most dogs had developed severe lameness by 5 to 8 months of age. The condition most likely had an autosomal recessive mode of inheritance, although genetic studies of mode of inheritance could not be performed.