Abstract

A geriatric, female bottlenose dolphin (Tursiops truncatus) with a history of bilateral nephrolithiasis was diagnosed with mild azotemia on a routine blood sample. In addition to long-term oral hydration therapy, she was receiving oral potassium citrate and citric acid treatment in an effort to decrease her risk of further stone formation. Ultrasound examination detected a partial ureteral stone obstruction with dilation of the left ureter and left renal collecting duct. Medical therapy was initiated and included low-dose tamsulosin, increased oral hydration, and tramadol, resulting in ~ 10 cm of stone movement within the ureter before stalling. An attempt to increase the tamsulosin dose was followed by two episodes consistent with fainting. Daily open-ocean swimming was added to the plan, resulting in further stone movement but not passage. Medical management was discontinued and the animal was prepared for surgical management under general anesthesia. Midazolam sedation was administered for patient preparation, followed by propofol induction for endotracheal intubation and maintenance on sevoflurane. The surgeons performed ureteroscopy and relieved the stone obstruction with laser lithotripsy. Following cessation of anesthesia and subsequent extubation, the animal was recovered in shallow water and monitored closely. Upon return to the ocean, medical management was reinitiated to facilitate passage of small stone fragments left behind by lithotripsy. She was restarted on oral potassium citrate and citric acid combination therapy with no evidence of adverse effects. General anesthesia was a key factor in the successful procedural outcome, as was involvement of surgical urologists and expert nephrologists in case management.

Acknowledgments

The authors thank Sacha Stevenson, Mark Baird, DruAnn Price, SSG Eduardo Quezada, SGT Steven Allen, HM1 Jose Garcia, and Drs. David Wenzler, Hossein Mirheydar, and Alissa Deming for their technical support. Dr. Mark Xitco, Brigitta Swenberg, and the U.S. Navy Marine Mammal Program training staff provided critical support for case management. Funding for urine physicochemistry and evaluation of medical treatment was provided by the Office of Naval Research Award #N00014110203.

* Presenting author