Abstract
Nephrolithiasis has been documented in bottlenose dolphins and can lead to urinary obstruction and renal failure.1-6
A 31-year-old male Atlantic bottlenose dolphin with chronic severe nephrolithiasis developed a ureteral stone obstruction in 2007, which was diagnosed in the left ureter via computed tomography (CT). Retrograde ureteroscopy under sedation was unsuccessful. Follow-up CT evaluation showed the animal passed the stone while receiving fluid therapy and supportive care. Ultrasound documented a reduction in blood flow and kidney size, consistent with atrophy.
In 2011, the animal developed clinical signs and azotemia consistent with acute kidney injury. Ultrasound, CT scan, and renal scintigraphy revealed focal hydronephrosis and proximal ureteral dilation of the functional right kidney; a stone present in the left distal ureter; and evidence of pooling and delayed excretion of the right kidney, suggestive of ureteral obstruction, respectively. Retrograde ureteroscopy under sedation was unsuccessful. The animal's condition deteriorated despite aggressive supportive care.
Laparoscopic-assisted ureterotomy was performed under general anesthesia. The right ureter was identified, incised, and examined proximally with a flexible ureteroscope. Unfortunately, the animal arrested, necessitating termination of the surgery. Despite resuscitation, the animal never fully recovered and was humanely euthanized.
Necropsy revealed severe bilateral nephrolithiasis; hydronephrosis of the right kidney; right ureteral distension with two stones present distal to the incision; one stone in the left distal ureter; and left renal atrophy and scarring.
We present a proof of concept for laparoscopic kidney surgery, which may be considered in dolphins with proximal ureteral calculus obstruction where conservative and medical therapies have failed.
Acknowledgements
The authors wish to thank the US Naval Medical Center San Diego for their ongoing medical and diagnostic support that aids in the excellent veterinary care of our patients. The authors also thank Drs. David Ward and Joe Ix, nephrologists from USCD Medical Center San Diego, for their consultations regarding this case. Special thanks to Jeff Dillon from Olympus Endoscopy for providing endoscopes; Fortech Medical for providing laser equipment, and Pacific American for their fluoroscopy assistance. Finally, the authors thank all of the veterinarians, trainers, and records office personnel that were instrumental in facilitating the care of this animal.
References
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