Hypertrophic Osteopathy: a Retrospective Case Control Study of 30 Dogs

209 Hypertrophic Osteopathy in Dogs INTRODUCTION Hypertrophic osteopathy (HO) is characterized by pathologic periosteal new bone formation (PNBF) (1). It occurs most commonly in humans and dogs, and has been described in other species (2, 3). It develops mostly secondary to various underlying conditions, classified as pulmonary, non-pulmonary intra-thoracic and extra-thoracic. Pulmonary pathology was recorded in 57/60 dogs with HO, commonly with metastatic lung disease (MLD) (61%), and primary pulmonary neoplasia (31%), and is more frequent in dogs with primary pulmonary neoplasia or osteosarcoma compared to those with other secondary MLD (2, 3, 4). HO was also found to be associated with other, non-neoplastic pulmonary lesions, including tuberculosis, abscesses, fibrosis, granuloma and chronic bronchopneumonia (2). It was also was described in 38% of dogs with spirocercosis-associated esophageal sarcoma, but not in benign spirocercosis (2, 3, 5). Other non-pulmonary, HO-associated intra-thoracic diseases include esophageal (i.e., chronic megaeosophgus and foreign bodies) and cardiac diseases (i.e., bacterial endocarditis and right to left shunt patent ductus arteriosus), dirofilariasis and rib tumors. Extrathoracic HO-associated diseases include American hepatozoonosis, hepatic failure, hepatic adenocarcinoma and primary urinary bladder neoplasia (3, 4, 6-10). Hypertrophic Osteopathy: a Retrospective Case Control Study of 30 Dogs