MULTIFOCAL IDIOPATHIC PYOGRANULOMATOUS BONE-DISEASE IN A DOG

Disseminated, multifocal idiopathic pyogranulomatous bone disease in a five-year-old neutered female crossbred cattle dog is described. The dog was presented for neck pain and reluctance to exercise. Radiograph y demonstrated polyostotic bone disease, the predominant change consis ting of a mottled pattern of osteosclerosis interspersed with punctate foci of osteolysis. Numerous bones of the axial and appendicular skel eton were affected including cervical vertebrae, ribs, scapulae and hu meri. Biopsy revealed sterile pyogranulomatous osteomyelitis. This was confirmed at necropsy which showed that lesions were restricted to bo ne. idiopathic granulomatous or pyogranulomatous conditions have been described in the dog in relation to skin but not bone. In people, idio pathic granulomatous bone disease is one of a group of conditions coll ectively called histiocytosis X, which are thought to be immunoregulat ory disorders related to T lymphocyte suppressor cell deficiency and L angerhans, cell proliferation.