How to Treat Sick Fish with Drugs

Fish can be treated with drugs in a variety of ways. Most antibacterial drugs can be given orally, by injection, or by external application. It is quite stressful to capture a fish and give antibiotics orally with an eye dropper. Medicated feed also has its drawbacks; a sick fish is often will not eat any food let alone an unpalatable drug food combination.

If an inexperienced hobbyist tries to give injections to a small fish problems are likely to occur. This procedure would severely stress an already sick fish and probably cause the drug to be given in the wrong spot.

Although some drugs must be given orally, most drugs are water-soluble and readily absorbed by the fish when placed in its aquatic environment. This method of treatment by absorption results in more consistent therapeutic levels of the selected drug and should an adverse drug reaction occur the fish can be removed promptly from the treatment solution.

All treatments, except copper therapy for white spot disease, are to be done in the quarantine or treatment tank and should not be done in the exhibition tank. The artificial seawater in the treatment tank must be fully prepared and have the same pH, salinity, and temperature as the main tank. In all but a few emergency situations the fish should not be fed for at least 24 hours prior to handling, transfer, and treatment.

The reason for a 24 hour period prior to handling is to free the fish's digestive tract of food and feces. Capture, tank transfer, and adjustment to a new environment cause stress. The adrenaline released into the bloodstream during stress causes a fight or flight reaction. Initially this reaction causes the digestion to shut down in much the same way your stomach gets a tight feeling during periods of anxiety. If the digestive tract is filled with food this stress could cause diarrhea which would complicate your treatment procedures. Therefore you should withhold food from fishes prior to treatment.

Many of the drugs recommended can be obtained from pet stores or from the local veterinarian by prescription. Chemicals whose medicinal use is limited to treating fish diseases can be easily obtained from a tropical fish store. Fish stores are also more likely to have small packages designed for purchase by the hobbyist. If you need to obtain the drugs from a pharmacy be sure to explain the intended use to the pharmacist. In many cases the pharmacist will provide additional information on proper handling and storage of the drug so that you can obtain maximum shelf life.