Marble bone - AKA osteopetrosis - AKA dense bone disease
Autosomal recessive in cattle - Angus, Simmie, Holstein
Bone is actually a pretty active tissue and is made and broken down on a daily basis resulting in "normal bone"
In normal long bone (ie leg bones) there is a central cavity where there is bone marrow - bone marrow is where the blood cells are made
In Marble bone there is a failure of bone resorption, ie it is not broken down but it is continually being made, resulting in very dense bone and obliteration of the bone marrow cavity
calves with marble bone are often aborted and may have short lower jaw
Some good pictures of the characteristic head appearance and long bones in the link below. This condition does require a necropsy for accurate diagnosis and is another one of those abnormalities where our 'old virus buddy' BVDV can muddy the diagnostic water.
http://www.vet.ksu.edu/features/VetQuarterly/KVQspr06.pdf
In addition to the 2 bulls listed on the RAA web site as carriers of marble bone, ABS has stopped selling semen on a full brother and is (as I understand it) doing father -daughter matings to confirm (or deny) his status as a carrier.
There is currently no test for marble bone - all suspected cases are going through the RAA
Autosomal recessive in cattle - Angus, Simmie, Holstein
Bone is actually a pretty active tissue and is made and broken down on a daily basis resulting in "normal bone"
In normal long bone (ie leg bones) there is a central cavity where there is bone marrow - bone marrow is where the blood cells are made
In Marble bone there is a failure of bone resorption, ie it is not broken down but it is continually being made, resulting in very dense bone and obliteration of the bone marrow cavity
calves with marble bone are often aborted and may have short lower jaw
Some good pictures of the characteristic head appearance and long bones in the link below. This condition does require a necropsy for accurate diagnosis and is another one of those abnormalities where our 'old virus buddy' BVDV can muddy the diagnostic water.
http://www.vet.ksu.edu/features/VetQuarterly/KVQspr06.pdf
In addition to the 2 bulls listed on the RAA web site as carriers of marble bone, ABS has stopped selling semen on a full brother and is (as I understand it) doing father -daughter matings to confirm (or deny) his status as a carrier.
There is currently no test for marble bone - all suspected cases are going through the RAA