Cor pulmonale secondary to pulmonary fibrosis in a 16-year-old mare

A 16-year-old mare was presented as an emergency to the Equine Hospital of the Veterinary School of Lyon, with a 1-month history of respiratory distress. On admission the mare was in poor body condition, with severe inspiratory and expiratory dyspnoea associated with severe hypoxaemia and marked tachycardia. Wheezes were auscultated. A pulmonary biopsy revealed fibrosis of about 40% of the parenchyma. Following an episode of atrial fibrillation, an echocardiogram was carried out which revealed signs of pulmonary hypertension, consistent with cor pulmonale. Despite the lack of aetiologic explanation for the primary pulmonary disease, the general condition of the mare improved with the administration of high-dosed corticoids and antimicrobial therapy.