Unfortunately, dropsy is often fatal without immediate, aggressive treatment, so you must quarantine the infected frog and seek veterinary attention as soon as possible. Dropsy is most commonly associated with African clawed frogs (Xenopus laevis) and dwarf clawed frogs (Hymenochirus spp.), but it may appear in other species.
Rather than referring to a specific disease or pathogen, "dropsy" is a term fish and frog hobbyists use to characterize a cluster of symptoms. Frogs with dropsy are often lethargic and may regurgitate their food, but the primary symptom of the syndrome is severe bloating of the abdomen and legs. Some frogs may continue to exhibit a strong appetite while suffering from the disease, but others may become anorexic.
Causes of the Condition
Dropsy usually results from a bacterial infection or as a response to a poor diet. Bacterially derived cases of the condition, which are often fatal, appear suddenly, while the bloating associated with diet-related problems occurs gradually. Infections arising from poor diet are not contagious, while bacterial infections may spread from one frog to another in the habitat.
Fixing Your Frog
Regardless of what form of the disease you suspect your frog is suffering, have your veterinarian examine your pet. In the case of a bacterial infection, he likely will prescribe a course of antibiotics; with luck, they will help your frog's immune system fight off the infection. In the case of a metabolic condition, your vet likely will counsel you to alter his diet to reduce the stress on his internal organs. While frogs often survive with this form of dropsy for extended time periods, your veterinarian may advise you to add some salt to his water, in hopes of drawing some of the water from your frog's tissues.
Treating the Tank
If your frog suffers from the bacterial form of the disease, you must strive to lower the bacterial population in the tank as much as possible. Start by emptying the tank completely and removing all of the substrate, plants, filters and cage furniture. Discard all filter media and everything porous; boil all durable furniture items for about 20 minutes to disinfect them.
Sterilize the tank by filling it with a 10 percent bleach solution and leaving it full for 24 to 48 hours. Empty the tank and rinse it thoroughly with clean, fresh water. Allow the tank to air dry for another 24 hours or so, rinse it out one more time, and refill it with dechlorinated water. You can then replace the furniture, substrates and other cage items.
If your frog is suffering from the bacterial form of the disease, poor husbandry is often to blame. Avoid repeat infections by keeping your frog's water clean -- use a three-stage filtration unit and perform regular water changes to help avoid a harmful buildup of bacteria. Avoid metabolism-related cases of dropsy by feeding your frog a varied diet, including high-quality commercial pellets, as well as small insects or larvae.