Steriod-responsive idiopathic interstitial lung disease in two dogs

Abstract

Two dogs had a 3 to 4 week history of persistent pyrexia, reduced exercise tolerance, inappetence and coughing and failed to respond to repeated courses of antibiotics. Clinical examination detected adventitious lung sounds, pyrexia and submandibular lymphadenopathy. Haematology in both dogs revealed an inflammatory leukogram. Both dogs had radiological abnormalities consistent with a multifocal interstitial lung pattern. Computed tomography performed in one dog had characteristic changes of cryptogenic organising pneumonia (COP), an extremely rare idiopathic interstitial lung disease. The abnormal pulmonary findings included several parenchymal bands, multifocal patchy ground-glass opacities and multifocal subpleural and peribronchial hyperattenuating poorly defined nodular opacities throughout the lungs. Bronchoalveolar lavage analysis in both dogs revealed a sterile suppurative exudate, excluding eosinophilic bronchopneumopathy. There was rapid resolution of clinical and radiological signs with corticosteroids and relapse in one dog after discontinuation of steroids supporting the diagnosis of this rare condition. Lung biopsy, which was not performed in either case, is definitive but considered invasive with major complications reported including death.