Swimbladder disease


What is a swimbladder?

The swimbladder is an internal organ that the fish uses to maintain its position in the water. It uses it to rise up, dive down or just to sit where it is. In fancy goldfish, it is like two balloons joined in the middle which sits underneath the spine, towards the rear of the fish. These are called the caudal lobe and the cranial lobe. The caudal lobe is closest to the tail, and the cranial lobe is closest to the head.  The swimbladder is filled with air and the fish can regulate the amount of air in the swimbladder to enable it to maintain buoyancy.

What is swimbladder disease?

True ‘swimbladder disease’ refers to an infection of the swimbladder which usually requires medication to deal with. The term ‘swimbladder disease’ is used to refer to any form of buoyancy problem experienced by a fish. It is this generic, and often inaccurate use of the term which frequently causes , misdiagnosis and inappropriate treatment. A more appropriate term would be ‘buoyancy problems’.


Potential causes:

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  • Poor water quality

  • A dietary problem

  • Stunting

  • A physical problem: the swimbladder organ has not developed properly for some reason

  • A deformed or compacted organ due to the nature of fancy goldfish body shapes

  • A bacterial infection: the fish has picked up a bacterial infection in its swimbladder which is causing it to malfunction – this is what most ‘swimbladder disease’ treatments are aimed at

  • A parasite infestation

  • Sudden drops in water temperature following a water change

  • A combination of one or more of the above

A lack of fibre can cause constipation; a blockage in the intestines can result in a build up of gas as the food starts to decompose inside the fish or leading to compression on the different lobes of the swim bladder. Gas in the gut can cause the fish to lose balance as the gut being underneath the fish mean that any digestive issues can easily flip the fish over.

Floating foods are best avoided as this reduces the risk of a fancy goldfish taking in excessive air while eating from the surface of the water. Too much food eaten in a short space of time can exaggerate swim bladder problems. Dry foods can be soaked for a minute or two before feeding, otherwise, they may swell up once the fish has eaten them and this could cause bloating and compression on the swim bladder.

To Conclude

If you suspect your fish’s problem may be dietary related, stop feeding for two days, then offer a small amount of cooked, de-shelled and chopped peas. Peas are high in fibre and provide a laxative, pushing through any blockages in the fish. Keeping the water slightly warmer, towards the upper end of the recommended range can also help, as warmer temperatures can speed up the metabolism and help the digestive system work. Daphnia and bloodworm fed as live or frozen food can sometimes help. A large number of hobbyists tend to use gel foods like Repashy super gold as it is easily digestible and packed with very high-quality ingredients. gel food is gentle on the goldfish digestive system as well as providing easily accessible nutrients. Find out more through the video below!