Name of disease: Costia
Other names:: Costia Necatrix.
Type of disease: Parasite.
Occurrence: one of the most serious parasites in goldfish
Symptoms include: gasping at the surface, slime patches around head and gills, sudden death (especially in spring), small hemorrhages under chin, spider web kind of lesions.
Treatment: Salt is the best, and most gentle way for the fish, to treat Costia. A salt solution of 0.3% is recommended, with 0.1% (1 tbs per 5 gl of water) added to the tank every 12 hours 3 times, so you are up to 0.3% after 36 hours. Some strains of costia have become resistant to salt, so the second best medication for it is QuickCure, or any medication containing Formalin. Potassium permanganate (PP) is also effective.
Precautions: Costia is a fast killer, if not treated immediately, since the parasite attacks the fishes gills. It is a parasite that can live in cooler waters as well, which is especially dangerous in the spring time when the fishes immune system is weakened, while the parasite is working full power.
Medications: QuickCure, Acriflavin, and Parasite Clear (Jungle Labs).