Respiratory distress, ataxia, and weakness in a ferret (Mustela putorius furo)

A 6-year-old 920-g neutered male ferret was presented for a 3-week history of respiratory distress, ataxia, and weakness.The ferret had a previous history of insulinoma and adrenal disease, which were managed with unknown doses of prednisolone and diazoxide as well as deslorelin implants.On physical examination, the patient was quiet, alert, responsive, and had a low body condition score (3/9).There was a palpably enlarged spleen, mild fluid wave, increased respiratory rate and effort, and muffled heart sounds ventrally.No murmur was auscultated.A thoracic point-of-care ultrasound on the conscious patient showed pleural effusion.The patient was hospitalized overnight on oxygen therapy, and respiratory effort worsened.A therapeutic thoracocentesis was performed, and an estimated 80 to 100 mL of serosanguinous fluid was removed.A CBC and plasma biochemistry panel were within normal ranges. 1 The patient was anesthetized, and an echocardiogram was performed (Figure 1).Formulate differential diagnoses, then continue reading.