Abscess on betta fish

The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.


Aquarium Advice Regular
Nov 15, 2021
My betta all of a sudden got this big white abscess on his side. He previously had dropsy I think, so I've been doing small water changes twice a day after I feed him so the water's super clean. He has been getting kanaplex through his food. He looked fine this morning, and his scales were starting to pinecone less, and go back to his side, but then I went to feed him just now and noticed this. He isn't using the fin on the side with the thing. He still is eating well though. He seems to be leaning weirdly towards the thing also. I don't know where or when he would have gotten injured or anything. Does anyone know what it might be and how I can treat it? I attached a few pictures so hopefully that will help.


  • IMG_6592.jpg
    173.2 KB · Views: 17
  • IMG_6597.jpg
    217.4 KB · Views: 11
  • IMG_6594.jpg
    196.4 KB · Views: 15
I can't tell for sure from these pictures but if the thing originates from the anus, that means there is a prolapse most likely from the pressure caused by the Dropsy. The anal sphincter muscle is not too weak to keep it all inside. If the thing originates through the skin, again it's most likely caused by a weakening of the tissue due to the pressure from the Dropsy. Since the fish is on Kanamycin, the chance for infection is low so I would continue the treatment for at least 2 complete therapeutic rounds ( approx. 2 weeks) then reassess for the next step.
Hope this helps. (y)
Top Bottom