Osteogenesis imperfecta in three dogs from a single litter

Three American Cream puppies from a litter of six were admitted for evaluat ion and treatment of lameness caused by multiple pathological fractures. Be cause of a poor prognosis, all three of the affected dogs were ultimately e uthanatized. Based on the histopathological findings of the bones and a col lagen analysis from cultured skin fibroblast cells which confirmed the pres ence of abnormal type I collagen, the presumptive diagnosis was osteogenesi s imperfecta. In humans, more than 90% of the cases of osteogenesis imperfe cta are caused by defects in type I collagen (11). Osteogenesis imperfecta has rarely been described in animals and none of the previous reports docum ent the disease in more than one dog from a single litter.