Batrachochytrium dendrobatidis in aquatic caecilians (Typhlonectes natans): a series of cases from two institutions

Infection with the fungal organism Batrachochytrium dendrobatidis was documented in two captive populations of aquatic caecilians (Typhlonectes natans), including 24 confiscated animals at the Bronx Zoo's Wildlife Health Center and two captive-born animals at the Phoenix Zoo. The animals at the Bronx Zoo were asymptomatic, and infection was discovered during quarantine polymerase chain reaction screening. Both animals at the Phoenix Zoo were clinically ill, and Batrachochytrium dendrobatidis infection was confirmed in both animals, but it is unclear what role, if any, the infection played in the animals' clinical signs. All of the Bronx Zoo's caecilians were successfully cleared of infection by elevating to and then holding water temperatures at 32.2 degrees C (90 degrees F) for 72 hr. One animal at the Phoenix Zoo died before treatment could be instituted, and the second died despite treatment with a 0.01% itraconazole bath. Chytridiomycosis has only been very recently first reported in caecilians, and much remains unknown about its behavior in this amphibian order. This is the first published report of Batrachochytrium dendrobatidis infection in captive-born caecilians and also the first describing details of treatment of chytridiomycosis in caecilians. It appears that raising tank temperature to 32.2 degrees C for 72 hr is a safe and effective treatment for aquatic caecilians with chytridiomycosis.