General Anesthesia and Exploratory Laparotomy in a Pacific White-Sided Dolphin (Lagenorhynchus obliquidens)
An approximately 22-year-old adult female Pacific white-sided dolphin (Lagenorhynchus obliquidens) maintained at the Vancouver Aquarium for 10 years presented with an acute onset of anorexia, lethargy, ignoring behavioral cues, and decreased fecal output. Bloodwork was monitored daily and revealed a progressively increasing inflammatory leukogram, increasing fibrinogen, decreasing serum iron, and increasing erythrocyte sedimentation rates. Aggressive medical therapy with fluids (oral and intravenous), antimicrobials, analgesics, and anti-nausea medications did not alter the clinical status. Within 3 days she developed peritoneal effusion and severe, progressive fluid dilation of the stomach chambers and long segments of small bowel. An exploratory laparotomy was performed on the evening of Day 4 and revealed necrohemorrhagic enteritis with no apparent obstruction or torsion. She recovered from anesthesia and surgery, but remained very weak and required around the clock supportive care. There was mild clinical improvement observed the following day including passage of approximately 100 ml of dark loose stool, but she deteriorated thereafter with a clinical pathology profile consistent with sepsis and profound inflammation. The dolphin died 3 days post-operatively. Necropsy confirmed abundant serosanguinous fluid with dispersed fibrin throughout the peritoneum, pericardial sac, and pleural space. There was a 1 cm long narrowing at the proximal limit of the colon. Orad to this narrowing, the small intestine was distended with acute hemorrhage and the walls were engorged with blood and edema fluid. Diffusely, the colonic lumen was reduced in diameter, contracted and featured prominent mucosal folds with no contents. Mechanical ileus is the prime consideration and was potentially multifactorial. Post-mortem abdominocentesis cultured E. coli and heart blood was PCR positive for Clostridium perfringens alpha-toxin.
To the authors' knowledge, this is one of the most complex surgical and anesthetic procedures ever attempted in a cetacean. Though the outcome was undesirable, this case clearly represents the aquatic veterinary community's collective advances in our ability to treat cetaceans in human care.
Our aquatic animal medical community contributed immensely to this case. The authors would like to specially thank Drs. Lesanna Lahner, Betsy Lutmerding, Eric Jensen, Christopher Dold, Sophie Dennison, Jenny Meegan, David Liu, Bill Van Bonn, Todd Schmitt, Hendrik Nollens and Cynthia Smith. Moreover, the incredible support from the Vancouver Aquarium during a very difficult time during which a quick and risky decision had to be made cannot be understated. We greatly appreciate the efforts of Brian Sheehan, Clint Wright, Adria Johnson, Chelsea DeColle, Kate Cooper, Gwyneth Nordstrom, our trainers, biologists, engineers, media and content departments and everyone else at our fantastic institution.
* Presenting author