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.