Swim bladder syndrome is can be seen occasionally in the aquarium. The swim bladder is an internal gas-filled organ that allows the fish to control its buoyancy, and thus to stay at the desired water depth without having to waste energy in swimming. A fish with swim bladder disorder will sink to the bottom or float to the top of the aquarium. They will have difficulty staying upright and may often be found floating upside down.
Swim bladder is common in fancy goldfish, “balloon” mollies and bettas and rare in other fish. This indicates a strong genetic connection, especially where the fish have been bred to be very round with a shortened spine. Also, fancy goldfish have a high incidence of these two diseases while comet goldfish almost never have them (again indicating a genetic connection). Over breeding and inbreeding can be dangerous.
Note that some varieties of fancy goldfish get swim bladder disease naturally and can live long and productive lives with the problem. Some folks even make the equivalent of a fish wheel chair to help their fish.
Big box pet stores typically have several fish in their tanks with swim bladder disease. This seems to be a very high occurrence rate. The reasoning for this is simple. Most tropical fish are flown in to fish stores. When the plane takes off it depressurizes to an altitude of 11,000 feet very rapidly. The swim bladder of the fish expands by 30% under these conditions. Then the plane drops again to sea level, pressurizing the swim bladder very rapidly. This rapid expansion and compression damages the swim bladder and makes it malfunction. Thus, the high incidence of swim bladder and dropsy in the fish in a fish store.
If the syndrome is in a fish that doesn’t have a genetic problem and hasn’t been recently purchased, the causes of swim bladder syndrome can be many different pathogens so it is difficult to treat. Treat by moving the fish to a hospital aquarium (can just be a tub) and treating with a mix of Metroplex and an antibiotic like Kanaplex or Maracyn 2 in the food.
It is easy to make medicated food. Heat 1/4 cup water (two ounces or 58 milliliters, not a lot) in the microwave. Then blend one 1/4 ounce of plain animal derived gelatin (Knox gelatin, one envelope) into the hot water with vigorous stirring. Take two tablespoons of dry commercial fish food (pellets or flake) and mix it with just a little of the hot water/ gelatin mixture. Add hot water/gelatin until you get a paste like consistency. If it gets too watery just add more food.
Then add roughly 1/16 teaspoon (a 1% to 2% addition) of the two medications to the mud. Mix and mash the whole mass thoroughly. Spread it out into a pancake about 1/8th inch (3 mm) thick on a plastic film or a plate. Then put in the refrigerator. If you plan on keeping it for more than two weeks put it in a small plastic bag and freeze. Note that the exact amount of medication which goes into the food is not very important. Antibiotics can be overdosed pretty much with abandon as they are only toxic in large doses over a period of months.
Some mild swim bladder disease cases may resolve themselves with this treatment. But like dropsy most cases of swim bladder disease indicate organ failure and are incurable and fatal.
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