Dropsy is a symptom of viral, bacterial or parasitic infections in fish. It is characterised by a bloated body. The scales of a fish with dropsy stick out so that the fish looks similar to a pine cone. Other characteristics of dropsy include lethargy, dulled colour, swollen or popping eyes and loss of appetite. Dropsy affects goldfish, bettas, tropical fish and other aquarium fish. Treatment for the ailment includes isolation, salt treatment and the administration of antibiotics.
Isolate your sick fish in a separate tank. Dropsy is not always contagious, but you do not want to risk having the infection spread to the rest of your tank. Lower the water level in the separate tank and add plants. This will give your fish easier access to the surface for air if that becomes a necessary oxygen supply. Add an air stone to the tank to increase the oxygen in the water if your fish gasps frequently or moves its gills rapidly, as these are signs that your fish is having difficulty breathing.
Relieve your sick fish's bloating discomfort by adding 1/2 teaspoon of aquarium salt per gallon of water to the isolation tank. Doing this will draw some of the fluids out of your fish's body and help relieve any pressure. Make sure the tank's water temperature remains at a comfortable level of around 25.6 degrees Celsius. Also be sure that the tank is clean. Poor water conditions and high nitrates are often the cause of dropsy.
Treat your fish with medication. There are different treatment options available at pet stores. You can choose from penicillin, tetracycline, nalidixic acid and other antibiotics. These treatments may come in the form of injections, baths or fluids. You can soak your fish's food in a mixture of antibiotic fluid and tank water. The fish will take the medicine directly into its body and start to benefit from treatment more quickly. Always be sure to follow package directions when administering medication to your fish.
Be prepared for the worst. Dropsy does not have a high survival rate. Even if your fish receives treatment early on, dropsy can irreversibly damage its internal organs. Your fish may die from kidney failure or other problems despite its recovery from dropsy.