Instructions
Look for any markings or spots on the goldfish's body. Tiny white dots on the scales, for instance, are indicative of ich, a common goldfish disease. Ragged fin edges most likely results from tail or fin rot.
Take notice if your goldfish is not passing the usual amount of feces, or feces are trailing behind the fish. This results from an inadequate amount of roughage in the fish's diet.
Note if the goldfish's swimming pattern has changed. If it's swimming on its side often, or swimming near the surface, it may have a swim bladder disease. A change in swimming behavior often is a key element in identifying a diseased goldfish.
Examine the goldfish's gills. If it appears the fish is breathing heavily, it may have parasites. Extending the gills wider than normal and a blotchy appearance to the gills may also indicate disease.
Observe any odd behavior. If, for instance, the goldfish is rubbing up against objects in the aquarium or fishbowl, this might indicate internal parasites or ich. Any change in the fish's usual behavior is most likely the result of disease.
Check the goldfish's eyes. While a fish's eyes naturally extend from the head, pop eye is an exaggerated distension that is the effect of disease, possibly tuberculosis or septicemia.
How to Identify a Diseased Goldfish
Goldfish are susceptible to several different diseases. Poor filtration, dirty water, getting too much or too little food or the water being too cold or too warm can all lead to disease. If you identify a diseased goldfish as soon as possible, you can most likely cure it before the disease progresses too far. Here's how to identify a diseased goldfish.