An approximately 31 year-old, 126 kg, adult female Pacific white-sided dolphin (Lagenorhynchus obliquidens) maintained in a semi-closed, 3.8 million litre captive display pool with a long history of intermittent gastrointestinal problems was presented with sudden anorexia, abdominal pain, and vomiting. The aging dolphin had had multiple antibiotic treatments in response to inflammatory blood profiles and inappetence at several public display institutions and was known as an “old dolphin that often goes off”. Although gastrointestinal disease had been suspected, the cause of the recurrent inflammatory changes in the peripheral blood was never definitively diagnosed. Starting in 2006, budding yeast and pseudohyphae were found on oral and gastric cytology in association with lethargy, inappetence and recurring inflammatory changes. Antifungal agents including oral itraconazole and nystatin were used and appeared to speed recovery and decrease the severity of the clinical signs. Repeated endoscopy of the esophagus and proximal stomach showed no significant lesions although a thick koilin coating of the stomach occasionally hampered close examination of the gastric mucosa.

In March 2009, the dolphin was being treated for recurrent gastritis suspected to be in association with yeast that was assumed to be Candida albicans based on cytological morphology. Treatment included nystatin and itraconazole and several antibiotics due to the unusually long course of her illness and poor response to therapy. She appeared to recover well and within 4 weeks was eating her normal diet and performing high energy behaviours. In May 2009, she was found anorexic and weak. Endoscopy of the proximal digestive tract and sonography of the thorax and abdomen revealed no significant lesions. However, over the next 3 days the animal declined very quickly. Abdominal radiographs revealed an unusual gas-filled loop of bowel in the craniodorsal abdomen and the dolphin showed repeated vomiting and severe abdominal pain. Oral fluids remained in the first chamber of the stomach for prolonged periods of time. Serum biochemistry results indicated hepatic disease and renal failure. The dolphin showed poor response to intravenous fluid therapy and continued to decline. Repeated abdominal ultrasonography revealed frank abdominal fluid and a decision to euthanize was made based on the probability of a perforated gastrointestinal tract and peritonitis. The dolphin died prior to injection of the euthanasia solution.