ALEXANDRIA, La. - About 600 Koi fish have died in the pond at the Alexandria Zoo, and the LSU's School of Veterinary Medicine say columnaris disease killed them.
Columnaris is one of the most common causes of illness in captive-raised fish. Two of the major causes of the bacteria are an increase in water temperature and a decrease in water oxygen levels.
The temperature in the Koi pond had been more than 80 degrees in the days leading up to the kill off. The night before and the morning of the fish being affected there was also heavy rain.
Officials say the heat and rain likely combined to cause the deaths of the fish.
