The bacteria that cause this goldfish disease are always present in the aquarium. However, improper feeding of your goldfish or poor water conditions can cause the bacteria to become active. Another reason that activates this bacteria is long periods of cold temperature in the aquarium.
Goldfish are cold-water fish, but that doesnt mean theyre immune to seasonal stress. As water temperatures drop: Their metabolism slows down. Immune responses weaken. Healing becomes slower.

The 6 Common Goldfish Diseases. 1. Goldfish Ich Disease (White Spot). goldfish with ich on quarantine.6. Popeye Disease. black pop-eyed goldfish in the fish tank. Image by: haireena, Shutterstock.

goldfish diseases picture. Ranchu x lionhead fancy goldfish with positive buoyancy disorder.If your goldfish looks like a water balloon, theres a chance he has polycystic kidney disease. We do not know what causes this in goldfish, but we see it quite a bit.
Goldfish diseases can be a common problem, Learn how to treat fin rot, swim bladder disease, fish fungus, lice and cotton wool disease and more.