Hypertrophic osteodystrophy in dogs.

Hypertrophic osteodystrophy is an uncommon orthopaedic disease that affects young, growing dogs. Aetiology is currently unknown; however, several unproven etiologies have been theorised in the literature including canine distemper virus, previous vaccination, hereditary causes and auto-immune disorders. Affected animals often present with varying degrees of lameness, lethargy, pyrexia and/or distal metaphyseal swelling of affected limbs. An index of suspicion is based on clinical signs. Confirmation is obtained with radiographs of the affected limb(s) by the presence of a "double physis," or a radiolucent line that is parallel to the physis. Treatment varies depending on degree affected, but generally consists of anti-inflammatory steroids, pain medications, gastrointestinal support, nutritional management and appropriate supportive care. Critically affected patients require intensive monitoring and more aggressive supportive care for prevention of life-threatening sequalae. Prognosis is very favourable with mildly and moderately affected patients, but good to guarded in severely affected patients.