This spring, the US Food and Drug Administration made legally available a treatment for a parasitic disease that commonly affects fish often kept in home aquariums and outdoor ponds.

Informally known as “ich,” pronounced ‘ick,’ or “white spot disease,” this condition causes white spots on a fish’s skin or gills, lethargy and decreased appetite. Ich is highly contagious and can kill all fish in a tank in a short period of time. It’s easily introduced into water by adding new fish or using equipment from an area housing infected fish.

The FDA has added Faunamor to its Index of Legally Marketed Unapproved New Animal Drugs for Minor Species. That makes Faunamor the only legal drug currently on the market to treat Ich. It’s available over the counter as a liquid to be added to tank water as directed.