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Diseases in Tropical Fish

Medicating Your Fish

(The First Tank Guide)

Selecting the Right Medication for Your Fish

When you decide to medicate your fish evaluate the medications available, and compare the symptoms they claim to treat to the symptoms your fish have.

Unfortunately, very few fish diseases are readily distinguishable to the untrained eye, and many diseases can only be accurately diagnosed through a necropsy or biopsy. Some even require special laboratory culturing for proper diagnosis, just as with human diseases.

Short of seeing a licensed veterinarian, your best bet is the best match of treatment to symptom. This often involves standing in front of the medication rack in the pet store and reading the labels of most of the medications.

In some locations, you may be fortunate enough to have access to a ichthine veterinarian - a vet who deals with fish. This professional can help you to properly diagnose your fish and select a proper treatment.

Never accept (or trust) amateur diagnosis, especially not a diagnosis given sight unseen. No honest aquarium expert or professional will tell you what your fish has without consulting with a veterinarian - a veterinarian who has examined the fish in question. Some pet store employees will help you select medication, but the good ones will be asking you about symptoms and then pointing you to medications that claim to treat that symptom. If the employee is telling you which medication to use based on a very brief description of what you think the fish has, don't expect their advice to be any better than your guess.

What About the Costs of Treatment?

Also, remember the fish and the costs involved in treating a disease. In some cases, it may be better for the fish (or for the finances of the fish keeper) to euthanize a diseased fish. This can put the fish out of its misery, and prevent long-time suffering as you try different medications looking for a correct match. Many fish can be euthanized by putting them in a container of water and freezing it, or you could try putting the fish in a solution of 1 part water and 2 parts hard liquor. This decision has to be made by the individual fish keeper, and cannot be recommended to all people.

I do not advise keeping your fish in a constant tonic of medications. As I mentioned on the disease page, medications are stressful to the fish and can actually increase their disease susceptibility. Also, if your tank is already medicated and the fish do get sick, the disease organisms that are infecting the fish are already immune to the medication you are keeping in your tank. It is also important that you complete full medication cycles any time you start medicating your tank. Even if your fish look better, the disease organism may still be present in the water, and those individual pathogens that have survived part of a treatment cycle are going to be more resistant to the medication than those that died earlier in the cycle. Medicating constantly and failure to complete medication cycles results in pathogens that are harder to treat next time. This also affects other fish keepers, as these medication-resistant pathogens spread from tank to tank.

Some fish keepers use salt baths or salt tonics to treat fish. This can be very successful for many diseases, but not all. Using a properly designed medication will give better results and be less stressful on the fish. Some fish also will not tolerate the added salt content in the water, so the salt treatment may be toxic to your fish. I do not recommend using a salt bath to treat fish for this reason, and because many fish can be sensitive to the salt content in their water, I do not recommend adding salt to a freshwater aquarium. However, if you do decide to treat your fish with salt, it is very important that you use a freshwater aquarium salt, as most salt that is not designed for aquarium fish contains Iodine, a nutrient necessary for people, but often toxic to fish.

Also remember to remove any carbon from your filter before medicating your aquarium, as the carbon, if it is working, should remove the medication from the water in under an hour, and if the medication is removed this quickly, you are not treating the fish. If the carbon is not able to remove the medication from the water this quickly, then it is saturated and should be replaced.

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