The swimbladder is the organ responsible for buoyancy and when there is a problem with it, a fish can have difficulty rising to the surface (“sinker”), difficulty swimming to the bottom (“floater”), swims on its’ side or swims in the nose down vertical position.
The following is a list of the causes of swimbladder disease (SBD) and what if anything can be done about them.

    • Viral infection: There is no specific medicine that will treat this and it may or may not get better.
    • Bacterial infection: This is a very rare cause of SBD, so one could treat with a medicated (anti-bacterial) food or an antibiotic like KanaPlex or MELAFIX Bacterial Remedy in the water, in a hospital tank, but the yield with this treatment is very low.
    • Dropping a fish: Uh… didn’t happen did it?! If your fish jumped out of the tank, the fall can bruise and even rupture the swimbladder organ. Only time will tell if this will heal. Bruises often heal but a ruptured swimbladder will not. Fast or feed your fish only very lightly for a few days after a fall to reduce stress on a potentially injured swimbladder.
    • Toxins: Hydrogen sulfide, from anaerobic bacteria, which gives a smell of “rotten eggs” to the tank’s water, water parameter abnormalities (unstable pH, elevated ammonia, nitrites or nitrates) and improper dechlorination (removal of chlorine) or dechloramination (removal of chloramines) can cause SBD. Proper water oxygenation, partial water changes and use of appropriate water conditioners may help. Medications can cause problems with equilibrium and may need to be stopped if SBD symptoms begin while treating.
    • Anatomy: Unusual anatomy in some fish, such as the stomach of globoid-shaped ornamental goldfish, makes them more susceptible to problems with the swimbladder. These fish are predisposed to impactions with food, which in turn clogs up the pneumocystic duct, which does not allow the swimbladder to inflate and deflate properly. Goldfish that lay or swim upside down are said to have “Flipover”.


  • Diverticulum: A weakening of the swimbladder wall or a visible “out-pocketing”, especially when occuring towards the tail of the fish, can cause floating problems. These fish often cannot get their tails below the water’s surface and “bob” there, tail up. Releasing the gas by puncturing the out-pocketing with a sterile needle and syringe might help. Perform this only as a last resort and get more specific advice before attempting this.
  • Overfeeding/constipation: This the most common cause of SBD! Usually, the abdomen (belly) is swollen when a fish is constipated. Also, fish that gulp air at the water’s surface when feeding can have swimbladder problems. The treatment is to withhold feeding for 24-72 hours or longer, and see if the constipation corrects itself. Examine what, how much and how often you are feeding the fish. Freeze-dried foods are notorious for causing constipation and swimbladder problems in fish.

For many fish, pre-soaking flake or pellet food (in conditioned water) is appropriate, as this will allow expansion of the dried food to occur prior to the fish eating it, and will lessen the chance of impaction. This may not be practical for a betta, who has a very small mouth, however a pellet can be broken into smaller pieces, soaked and then fed. Switching to frozen or live food would be helpful. A pelleted-food product for goldfish, ProGold, is touted as causing little to no constipation. Feeding sinking foods eliminates problems from air gulping. If the fasting does not work in a few days, then you may wish to try feeding a tiny piece(s) of frozen (but thawed) shelled pea, as this may help to dislodge any impaction. For bettas, these pieces of pea must be very small.

As a last resort for treating constipation in a betta, an Epsom salt bath can be performed. This is very stressful on a betta but a betta can die from constipation, so if no poo is seen after withholding food for one week and feeding tiny pieces of a frozen (but thawed) pea after 3-4 days of fasting, then this is worth a try.

Epsom Salt Bath for Betta Constipation:

  1. 1 Tbsp. Epsom salt
  2. 1/2 gallon conditioned water
  • Mix equal parts of your fish’s current water with Epsom water. You can use just about any measurement, e.g. 1 pint, 1 quart, etc., just as long as you use an equal amount of Epsom water and tank water. Do not use Aquarium or other types of salt.
  • Make sure that you have enough of the old water left to put the fish back into, replacing the missing water with new conditioned same-temperature water.
  • Add your betta to the Epsom/tank water mixture for 15-60 minutes or until he poos (whichever comes first). If after 60 minutes in the water, he has not pooed, take him out and put him back in his old tank water and watch him over the next few hours.
  • Even if he does not poo in the Epsom/tank water, usually he will poo later after he has been removed.
  • If at anytime, while in the Epsom/tank water, he rolls over and stays there (such as on his side or upside down), then you will need to remove him immediately and put him back into his tank water.

One can burp larger fish manually, although this is to be avoided unless the fish is starting to fail. This can be done by applying gentle pressure to the underside of the fish, from just in front of the vent (anus) and sliding a finger forward toward to the mid section of the belly. If successful, one will often hear an audible ‘burp’. One should then use a little Stress Coat or NovAqua afterwards because the handling of the fish may damage its’ slime coat.

Be sure that there is nothing in the hospital tank for the fish to injure itself upon because of the swimming difficulties. For example, a plastic (sharp) plant might injure the eye of a fish who is swimming awkwardly on its’ side.

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