HistoryAn 8-week-old 5-kg (11-lb) sexually intact male English Bulldog was evaluated by a referring veterinarian for dyspnea and weakness of 12 hours' duration. The dog was treated with furosemide (2 mg/kg [0.9 mg/lb], IM) and oxygen supplementation, which resulted in mild improvement in signs of respiratory tract disease.On physical examination, the dog had signs of depression with pale mucous membranes and weak femoral pulses. Inspiratory effort was increased with a marked abdominal component. Heart sounds were muffled, and jugular veins were distended and pulsatile. The abdomen was distended. Results of a CBC and serum biochemical analyses were within reference limits. Radiographs of the thorax were obtained (Figure 1).Determine whether additional imaging studies are required, or make your diagnosis from Figure 1-then turn the page →