Koi fish undergoes successful out-of-water medical procedure at San Diego Zoo

A Fish Out of Water—but Only Temporarily: Koi at San Diego Zoo Undergoes Medical Procedure
While San Diego Zoo veterinarians are well known for providing potentially lifesaving medical procedures for cheetahs, orangutans and rhinos, among others, sometimes the patients are much smaller. Recently, a koi fish at the San Diego Zoo underwent a medical procedure, to remove masses from its body. While it generally isn’t safe for a fish to be out of water, this koi was in good hands, attended to by wildlife care specialists at the Zoo.
Wildlife care specialists noticed a skin mass on the approximately 35-year-old koi as the fish was swimming in its pond at the Zoo’s Terrace Garden. The fish was moved to a tank and transported to the veterinary hospital at the Zoo, where it was placed on a specially built table for fish exams. It was anesthetized and water was continuously run over its gills to allow it to breathe, while a Zoo veterinarian safely examined the fish and removed the masses.
There were three skin masses removed from the koi. The concern was that the masses could become ulcerated and affect deeper tissue. The masses were determined to be spindle cell carcinoma, which may return in those areas, but should not spread to the rest of the body. The koi was returned to its 18,500-gallon pond the same day as the medical procedure. It is currently eating normally, and the surgery sites have all healed well. The koi will be monitored closely for any recurrence of the masses.
Koi are ornamental varieties of domesticated common carp that originated in Japan. At the Zoo, they live in outdoor ponds with clean, oxygenated water and plenty of shade, as they are susceptible to sunburn. Koi are culturally significant, and represent love and friendship in Japan. Some koi have been known to live more than 200 years.
###
Photo was taken on May 15, 2020 by Ken Bohn, San Diego Zoo Global