Osteopetrosis

Osteopetrosis is a rare disease that appears to be inherited as a simple autosomal recessive trait in Angus, Simmental, and Hereford cattle. It is also seen in dogs and foals. It is characterized by premature stillbirth 10 days to 1 mo before term, brachygnathia inferior, impacted molar teeth, and easily fractured long bones. Bone marrow cavities are absent and replaced by primary spongiosa. The fetal-like abnormal intramedullary bone consists of chondro-osseous tissue. Foramina of the skull and long bones are hypoplastic or aplastic. The cranium is thickened and compresses the brain. Extensive mineralization is present in vessel walls and neurons of the brain. Diagnosis is confirmed by a longitudinal bisection of long bones revealing the diaphyses filled with a plug of bone instead of marrow.