Sick Betta fish behavior can indicate that something is wrong with the fish, and since Siamese fighting fish are relatively small fish it could be hard to track their health. However, there are several of key indicators signals that something is certainly going not right.
Sick betta fish behavior
Lethargy, or chronic laziness and low movement/strength, can be associated with lots of Siamese fighting fish diseases and it is bad news.
Perhaps description for such behavior is probably that you are introducing a Betta to a whole new home, or you happen to be experiencing water quality control issues. Most Betta splendens diseases are associated with poor water quality, ensure that you are making regular water changes.
Lethargy could also be caused when the water temp drops below the acceptable 78-82 degrees Fahrenheit, and if this is the case then adjusting your heater will make a simple fix to the issue.
Refusal to Eat
Another indicator with numerous explanations, whoever has owned a Betta has likely encountered this issue at one point or another. That is most common in Chinese fighting fish that are first brought home could be stressed.
Another cause is constipation, in which particular case your fish has simply been overfed. Obviously, you will need to change your feeding amount.
There are two reasons why the betta fish color fades the stress and old age. Stress can be bad for a Betta so that it is preferred that you make an effort to identify any loud noises, bright lamps, temp fluctuations, or irregular light/dark patterns around your Betta’s container in order that they feel convenient.
Old age cannot be reversed as easily, and you will have to simply accept that your betta is getting into his fantastic years, don’t get worried though, usually stick around for some time after they begin to dull in color.