Signs of fish disease will depend on the nature of the disease, which can be bacterial, fungal, parasitic, protozoan, viral, and a host of non-infectious and miscellaneous diseases. The type of disease can also depend on the breed of fish, and whether it is fresh or saltwater.

The type of disease will also greatly determine which signs are apparent, helping in pinpointing the problem.

Though the list of all the types of fish disease is too great to include here, some signs are easier to spot in your fish, and many could be an indication of several different types of diseases. For instance, parasitic problems are normally indicated by your fish rubbing or scraping itself against other objects, loss of weight, gill or fin problems, or actually seeing paratistes on or coming out of the fish's body.

Fungal attacks normally follow some other health problem, such as like parasitic problems, injury, or bacterial infection. Signs of this sort of fish disease are normally gray or whitish growths in and on the skin or fins of the fish. When left untreated, these growths will probably become cottony looking and will eventually eat at the fish's body until it dies.

Signs of fish disease which involve color change, growths, slime, breathing problems, changes in scales, fins or other body parts, can be an indication of a variety of fish diseases. As with any animal problem, it is important to do your homework, as the type of condition, problem, or disease your fish has will also determine what treatment will be used. Since most fish are very sensitive to environmental and other changes, it is important that the correct medications and/or treatments are used and that they are in the correct doses - you would not want to further endanger your already ill fish.

There are many sources which will help you determine the nature of disease or other problem your fish has, and will help you recognize the signs. Many internet sites, books, and other fish care guides contain charts and other information to help you in both determining and in treating your fish's problems. Also, experts on fish care, which include veterinarians and local pet/fish store employees are a great source, and they are sometimes able to diagnose simple problems by your description.

The most important things to remember are to do your homework, and to keep your fish's safety in mind. The good thing is that most signs of fish disease are very apparent, and most fish disease is treatable.