Fish deformities and why they happen
Deformities in fish can be very alarming and unfortunately are often the result of genetic malfunctions, viral infections or tumours which are not directly treatable.
In much the same way as humans, the best way to treat viral infections is to support the body’s immune system which will fight off the problem.
(Note – if your fish has developed a swollen or protruding eye this could be pop-eye, an internal bacterial infection. See Internal Bacterial Infections for more information).
Primarily due to heavy interbreeding, some fish are born with genetic conditions which mean they are misshapen or malformed from birth; a twisted spine being fairly common. It is not recommended to buy a fish like this.
If you do have fish with physical deformities, and it is eating and not being bullied, then supporting the aquarium with Disease Away or Aqualibrium First Aid Salt Additive will be enough to keep them well. They might not have a long life but you will have done all you can for them.
Carp Pox/LV and Tumours
Large swellings or lumps which develop under the skin are usually tumours (often caused by a genetic predisposition) which are unlikely to disappear. If the tumour is benign and does not affect swimming, breathing or feeding the fish can often continue live for many years.
There aren’t any specific treatments for fish viruses or tumours, however you can give your fish the best quality of life by maintaining a healthy environment and feeding a good quality diet.
Consideration to aid the immune system of your fish and reduce stress include: