Pulmonary thromboembolism is an uncommon but likely under-diagnosed condition in small animal medicine owing to both lack of awareness and difficulty in making an antemortum diagnosis (1). Pulmonary thromboembolism (PTE) occurs when a thrombus, thrombi, embolism, or emboli causes occlusion of one or more pulmonary arteries (1). Besides hypoxemia, this occlusion of the perfusion to the lungs can result in severe pulmonary hypertension, eventually leading to right sided heart failure (cor pulmonale.) Because of this ventilation/perfusion mismatch and secondary right-sided heart failure, patients with pulmonary thromboembolism often present in acute respiratory distress. Pulmonary thromboembolism carries with it a guarded to grave prognosis, despite proper diagnosis, intervention, and treatment. The goal of this report is to use a real case of pulmonary thromboembolism to distinguish pulmonary thromboemboli from other causes of acute respiratory distress; to identify common presenting complaints and associated clinical signs, physical exam findings, and predisposing factors for pulmonary thromboemboli; and to discuss diagnostic and treatment options available.