Goldfish Diseases
One of the more common goldfish diseases is called Ich. Also fins that are split, holes in the fin or chunks of the fin flaking off the goldfish. Fin rot is easy to treat, but you need to find out what the cause of the illness was to prevent the disease happening again.
Dropsy is one of the many bacterial infections that your goldfish can succumb to. This bacteria works from the inside out. Typical outward appearances of this are you fishes scales sticking out. Dropsy is also a cause of high stress like, overcrowding, fluctuating temperatures, and even fighting with other fish.
Ick looks like there is salt on the goldfish, the goldfish will rub itself against objects in the aquarium because of irritation. The goldfish can also have ragged fins, and fast moving gills