Excerpt from Popular Amphibians, part of the Advanced Vivarium series with permission from its publisher, BowTie Press, a division of BowTie Inc. Purchase Popular Amphibians here.
Velvet disease, a type of skin infection better known in fish, also infects aquatic amphibians. The gray, slightly fuzzy, discolored skin and gill patches associated with velvet disease can mislead you into believing the lesions are caused by a fungus. In fact, they are caused by the dinoflagellate protozoan parasite, Oodinium pillularis. Treatment for velvet disease consists of changing water, keeping temperatures toward the warm end of the ideal range, and bathing affected amphibians in salt baths (50 to 100 grams of sea salt per gallon for fifteen to thirty minutes daily). If the infection is extensive, administer an antibiotic to prevent secondary infections.