Osteochondrodysplasia in bull terrier littermates

A four-month-old male bull terrier with an abnormal hindquarter gait was found to have changes suggesting nutritional secondary hyperparathyroidism, together with unusual large foci of non-ossified material in both femoral necks and similar smaller foci in metaphyses of several long bones. Abnormal cartilage was found in the one femoral neck examined at autopsy six weeks later, with features suggesting impaired vascular remodelling of cartilage due to failure of chondrocyte maturation. Similar clinical and radiographic abnormalities were found in three littermates (one male, two females), but not the dam. The status of six other littermates and the sire is unknown. The femoral neck lesions had healed in two pups re-examined eight months later, but some limb bones remained abnormal in shape. The abnormalities in affected pups suggested osteochondrodysplasia.