Osteodystrophia fibrosa in horses at pasture in Queensland: field and laboratory observations

Horses grazing manily Cenchrus ciliaris and/or Panicum maximum var. trichoglume pastures on over 30 properties in southern central Queensland developed lesions of osteodystrophia fibrosa. Horses on individual properties in coastal Queensland grazing Setaria anceps, Brachiaria mutica or Pennisetum clandestinum also developed the disease. Ill-thrift, lameness, and fibrous swellings of nasal bones, maxillae and mandibles were observed. Calcium and phosphorus levels of pasture were normal but all the above pasture species contained oxalates which were suspected of causing the disease.