Hypertrophic osteopathy associated with infective endocarditis in an adult boxer dog

Abstract

A 20-month-old, entire male boxer dog was presented with lethargy and intermittent shifting limb lameness. Diagnostic tests revealed aortic valve vegetations suggestive of infective endocarditis causing severe aortic outflow obstruction, and hypertrophic osteopathy of all four limbs. The dog was treated symptomatically and euthanised four days later. The association of infective endocarditis and hypertrophic osteopathy has been poorly documented in the veterinary literature. The pathogenesis of hypertrophic osteopathy is unknown; however, four theories have been put forth to explain this disease: pulmonary shunting, vagal nerve stimulation, humoral substances produced by neoplastic cells and megakaryocyte/platelet clump hypothesis.

Hypertrophic osteopathy associated with a bronchial foreign body (grass awn) in a dog: a case report

“…Hypertrophic osteopathy has been reported in different species and is generally associated with primary or secondary neoplasms in the lung or thoracic cavity (Hancey and Pass 1972;Lavi et al 1982;Caywood et al 1985;Hirakata and Kitamura 1995;Amstrong et al 2007;Dunn et al 2007;Fridlington et al 2007), as well as occasionally also by intraabdominal lesions (Halliwell and Ackerman 1974;Peeters et al 2001). Reports of HO associated with non-neoplastic thoracic lesions are less frequent and may include inflammatory lung disease, heart-worm disease, bacterial endocarditis, oesophageal disease secondary to Spirocerca lupi infestation, eosinophilic bronchitis, pulmonary abscess and congenital megaesophagus (Murray 1968;Caywood et al 1985;Watrus and Blumenfeld 2002).…”

“…For example, increased blood flow to the distal extremities may occur, with subsequent stimulation of connective tissue apposition and local osteogenesis that typically starts in the digits and extends toward the axial skeleton (Allan 2002); alternatively, a neural autonomic reflex that originates in the thorax and modulates the connective tissue and periosteum growth of the limbs may be involved. Furthermore, the metabolites produced by tumour cells might stimulate new bone formation at distant sites or megacariocytes originating from the bone marrow might migrate to pulmonary capillary beds and give rise to mature platelets by budding (Hancey and Pass 1972;Lavi et al 1982;Caywood et al 1985;Barrand and Scudamore 2001;Peeters et al 2001;Dunn et al 2007).…”

“…The mechanisms of HO development are not completely understood (Caywood et al 1985); several theories have been proposed to explain the pathology (Dunn et al 2007). For example, increased blood flow to the distal extremities may occur, with subsequent stimulation of connective tissue apposition and local osteogenesis that typically starts in the digits and extends toward the axial skeleton (Allan 2002); alternatively, a neural autonomic reflex that originates in the thorax and modulates the connective tissue and periosteum growth of the limbs may be involved.…”

“…Hypertrophic osteopathy (HO) is an uncommon disorder characterised by a painful periosteal reaction and oedematous soft tissue swelling of the limbs usually associated with intrathoracic disease (Dunn et al 2007). Radiographically, HO is characterised by new periosteal bone formation starting in the digits and extending toward the axial skeleton (Caywood et al 1985;Dunn et al 2007).…”

“…Radiographically, HO is characterised by new periosteal bone formation starting in the digits and extending toward the axial skeleton (Caywood et al 1985;Dunn et al 2007). …”