What is Abdominal Dropsy and how can you treat it?

Abdominal Dropsy is a disease that is caused by bacteria and viruses that are found in almost every aquarium. Almost all fish species can be affected. Even without a specific host, the bacteria can reproduce for months in the water, substrate and filtration of an aquarium.  Since they belong to the normal bacterial flora of the tank, healthy fish can resist them until they are stressed by unsanitary conditions, aggression, improper diet or temperature.

When infected a fish releases large amounts of bacteria often exposing its tank mates to the disease. Infected fish swell up (almost to bursting point and can look like they have swallowed a golf ball) as they are unable to dispose of excess fluid in their body cavity. Their scales can often be raised and their eyes too can look like they are about to burst. Severe infection can result in damage to the gallbladder liver and kidneys eventually resulting in death. The symptoms can appear singularly or all at once and this disease can kill fish very quickly.

Here is one of my Tropheus moorii Chaitika that when stressed by aggression contracted the disease.

In this picture you can notice the distinct swelling of the eyes AKA pop-eye.

Here the abdominal swelling is very noticable.

Compare the two fish in this photo

Notice the raised scales in this photo

The fish above was successfully treated and returned to the colony within a week. I treated with 2 satchels of Furan2 and 2 x 200mg Metro Tabs to 10 Liters of water. I also added 1 full cup of epsom salts. I kept them in the bath for 2 hours twice a day for 2 days. At the time the Furan and Metro were the only drugs I had on hand other than Clout (which I did try treating with to no avail). In hindsight, I believe that the Metro had no affect whatsoever on the abdominal dropsy and that I probably should not have used it. I have also treated for abdominal dropsy with Tetracycline in conjunction with Epsom Salt and witnessed a faster recovery by the fish.

I have recently discovered that there are several medications that can treat abdominal dropsy however, Tetracycline is the easiest for aquarists to obtain. To treat in a hospital tank over a long term (4 days) use 1 gram of Tetracycline per 100 liters of water. To treat in a bath over 24 hours you can dose 100mg per 1 liter of water. Because Tetracycline is not highly soluble it is recommended that you dissolve it in warm water before adding to the tank or bath. As this medication is photosensitive it also recommended that cover the tank or bath for the duration of treatment.