Velvet (also known as Oodinium; highly contagious). This is very difficult to detect initially, because the fuzzy area that grows has a yellow or golden color, and on a goldfish it is hard to find. Commercial treatments for this fungus are best. Some experts use malachite green or the old-fashioned salt bath. If your pet store doesn’t have a commercial treatment, which it should, I suggest that you use the ten-day salt-water treatment

Also, make sure to place some sort of antifungal chemical in the water in the aquarium, so as to disinfect the tank.

Fungus (also known as Saprolegnia; highly contagious) Generally a fuzzy growth, it is different from velvet because it is whiter and easier to notice; Some experts paint the affected areas with methylene blue and place the fish in a ten-day salt-water treatment.

Again, commercial treatments are usually available, either through pet stores or catalogs.

Related posts:

1. The Basics of Pet Goldfish: The Old-fashioned Salt Bath

2. The Basics of Pet Goldfish: Diseases of the Goldfish

3. The Basics of Pet Goldfish: Fin Congestion

4. The Basics of Pet Goldfish: Fish Pox (probably not contagious)

5. The Basics of Pet Goldfish: Hand-Stripping

6. The Basics of Pet Goldfish: Leeches (highly contagious)

7. The Basics of Pet Goldfish: Fish Lice (highly contagious)

8. The Basics of Pet Goldfish: Feeding Fry

9. The Basics of Pet Goldfish: Pond Keeping

10. The Basics of Pet Goldfish: Emergency Cleaning