Drug for treating common disease in pet fish is now legally available

The FDA is making an unapproved antiparasitic and antimicrobial drug legally available for use with ornamental finfish such as goldfish, discus, koi, and tropical fish species. The drug Faunamor is used for treating Ichthyophthirius multifiliis, which is also known as “Ich” or “white spot disease,” in fish commonly kept as pets in home aquariums and hobby ponds.

Photo: Ovidiu Iordachi/Adobe Stock

Manufactured by Aquarium Münster Pahlsmeier GmbH in Telgte, Germany, Faunamor contains a trio of active ingredients including methylthionine chloride, malachite green oxalate and acriflavine chloride immersion solution. According to the FDA, Faunamor has been added to the FDA’s Index of Legally Marketed Unapproved New Animal Drugs for Minor Species and is the only legal drug for treating white spot disease that is currently on the market. It is available over the counter in 20 mL and 100 mL glass bottles.

The parasite that causes white spot disease can be introduced into a pond, tank, or home aquarium simply by adding new fish or equipment that has been moved from another unit infected by Ichthyophthirius multifiliis. White spot disease is highly contagious, can spread rapidly between fish, and affects many types of ornamental fish. Infection outbreaks can kill all the fish in the tank, aquarium, or pond in a short time, according to the FDA.

Fish infected with white spot disease may appear weak or lethargic and not want to eat. However, the most common sign of infection is the presence of small, blister-like white spots on a fish’s skin or gills.

An expert panel evaluated the safety and effectiveness of Faunamor as part of the indexing process, which is a quicker and less expensive path to legal marketing status for certain products than the drug approval process. The indexing panel concluded that the benefits of using this drug outweigh its risks to ornamental finfish. Other unapproved drugs being used to treat white spot disease have not been reviewed by the FDA for safety and effectiveness, according to the agency.

Reference

FDA announces new drug treating common disease in ornamental pet fish. News release. FDA. April 8, 2025. Accessed April 8, 2025. https://www.fda.gov/animal-veterinary/cvm-updates/fda-announces-new-drug-treating-common-disease-ornamental-pet-fish?utm_medium=email&utm_source=govdelivery