Swim bladder disease, or swim bladder disorder, occurs when the swim bladder (a gas-filled sac located toward the fish's tail, which assists with buoyancy) is compromised because of distension in the stomach, bacterial infection or trauma. Symptoms of swim bladder disease include difficulty swimming, swimming upside down or on its side, inability to dive, or a visibly distended abdomen. Round-bodied fish, especially fancy goldfish such as orandas and black moors, seem to to be more prone to swim bladder disease than long-bodied fish.
Overfeeding is one of the most common, and most easily curable, causes of swim bladder disease. Constipation causes a distended stomach, which affects the swim bladder. If your fish displays inability to right itself soon after eating, you can try reducing the amount of food per feeding. Petfish.net states that it is safe to let your fish fast for a couple of days to allow the stomach to empty.
A fish that eats a consistent diet of dried foods, such as pellets, may develop swim bladder disease. According to Paradise Pet Shop, fish owners can try soaking pellets before feeding to make them easier to digest. Owners also should introduce food packed with fibre, such as squash, spinach, zucchini, peas, romaine lettuce and grated carrots.
Water Quality and Bacterial Infection
Another possible cause of swim bladder disease is poor water quality, which results from overstocking your aquarium or improper filtration. A build-up of ammonia, nitrates and nitrites from fish waste may cause a bacterial infection, which inflames the fish's swim bladder. Once the water quality problem is solved, infected fish will need to be quarantined. Many aquarium owners treat the afflicted fish with a fish-safe antibiotic such as erythromycin, minocycline or tetracycline.
Old School Treatment
The old-school cure for swim bladder treatment is simple: Feed the fish a boiled pea. According to Dr. Greg Lewbart, professor of fish medicine at North Carolina State College of Veterinary Medicine, offering a cooked pea daily to a fish with swim bladder disorder may help break down impaction in the fish's stomach that interferes with swim bladder function.
State of the Art Treatment
According to Dr. Doug Mader of Marathon Veterinary in the Florida Keys, the best cure for swim bladder disease is a visit to a fish-knowledgeable veterinarian. The veterinarian will test the inside of the swim bladder and identify the cause of the disorder, prescribe antibiotics or dietary changes as necessary, and even may surgically remove some of the air from the swim bladder to make the fish more comfortable immediately. Another veterinary technique involves surgically inserting a small stone in the fish's abdomen to help weigh it down.