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 chosen and that they are in the correct doses - you would not want to further endanger your already ill fish.
Another important thing to remember when treating your ill fish with medication is that not all medications work for all ailments. This is especially true with parasitic problems. Some treatments are as “simple” as adding the correct doses to your aquarium. Others require that your fish be removed and medication be applied directly to your fish.
It cannot be stressed enough that, whichever medicine or method of application be the correct one, as to not further endanger your fish’s health.
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 your fish's problems, and in choosing the correct fish medication and its application. 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.
Again, 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 fish disease and injury are treatable, as long as you are careful in choosing and treating your fish with the correct medication.
