Osteopetrosis letal hereditaria (enfermedad de los huesos de mármol) en terneros Aberdeen Angus en Uruguay

Congenital osteopetrosis was diagnosed in red and black Aberdeen Angus calves from two herds in the east region of Uruguay. Five calves (6.8%) were born dead in a purebred Red Angus herd in August 2009, and 3 (7.5%) in a Red x Black Angus cows in November 2010 (7.5%). Both herds were bred with Uruguayan Red Angus bulls. The major gross findings of two necropsied calves were deformed facial and cranial bones, severe brachygnathia, impacted lower molars, and lack of bone marrow cavities in the long bones. Histopathological examination revealed abnormal bone resorption which resulted in persistence of primary spongiosa obliterating the bone marrow cavities. Blood samples from one bull and two dams from one of the affected herds were identified as carriers for the SLC4A2 mutation. It is suggested that the mutation is widespread in Red Angus herds in Uruguay