Chytridiomycosis in an Aquarium Collection of Frogs: Diagnosis, Treatment, and Control

Abstract

The introduction of a new group of dendrobatid frogs to an established captive amphibian collection was followed by several acute mortalities in both resident and introduced frog populations. Chytridiomycosis, caused by Batrachochytrium dendrobatidis, was diagnosed by histology in two of the dead frogs. Following the diagnosis, all amphibians were moved to a specially made quarantine room with strict handling protocols and treated with itraconazole. Frogs, being terrestrial amphibians, were treated with itraconazole (Sporanox, 10 mg/ml) at 0.01% in 0.6% saline in a 5-min bath for 11 consecutive days. Axolotls (Ambystoma mexicanum) and Kaup's caecilians (Potymotyphlus kaupii), being aquatic amphibians, were treated with itraconazole administered directly in their primary tank water to achieve a concentration of 0.01% for 30 min every 5 days for four treatments. Itraconazole was removed from the tank water after 30 min by high-rate-of-flow activated charcoal filters. The treatment and quarantine procedures were successful in eradicating the disease. The few amphibian mortalities that occurred in the 18 mo after the start of the treatment have been histologically negative for the presence of chytrid fungi. The collection is now considered free of chytridiomycosis.