Hi!
I see a lot of members are replying that it maybe Lymphocystis or a tumor. Earlier this year I had a betta with a similar issue and made a post on here as well. At the time it was very hard to find information of treatments or cures especially because these kind of conditions can be gene related. For my betta it started as a small white dot and it rapidly grew (early pictures are on my post). I tried pretty much all the advice I could find online. I quarantined my betta and treated him with various medicines including both maracyn 1 & 2. The ball kept getting bigger and bigger, eventually causing very bad fin rot. After noticing the medicine was not really helping with neither the fin rot or the "tumor," I decided to turn to another option. At this point my betta's tail fin had deteriorated so rapidly it was almost fully gone. Luckily, he never stopped eating but his health was obviously getting worse. After plenty of research I found multiple videos about how to physically remove the tumor yourself. At first I was very hesitant, but seeing the situation, it was probably the final option. I decided to lay the betta off the medicine and simply treated him with a little bit of salt for a few days (I used the salt procedure Cory recommends). Then the day came when it was time to operate the poor guy.
I set up a clean disposable plate with a wet paper towel. I used those kitchen towels that do not easily fall apart when wet, so you can keep the fish wet during the procedure. I folded the towel over the rest of his body and held em down gently. At this point I noticed the tumor was so weakly attached (Foo also mentions this in his video) so instead of using tweezers, I used a q-tip dipped in 3% hydrogen peroxide and was able to brush it off. I then got another q-tip and apply a bit more peroxide to the little hole left by the tumor. Finally, I also gently used another q-tip to remove some of the dead rotten fin that was still hanging off the poor guy.
After, I returned him to his clean quarantine tank (did a water change right before the procedure) and the poor guy sank right to the bottom. At that moment, he looked horrible. I honestly panicked, I thought I had just killed my little friend. However, there was not much left to do so I turned off his light and let him rest. In 15 minutes to my surprise he was back to swimming, I even fed him a single pellet to see if he would eat it and he did! After that his wound fully recovered in a day and he was back to being very active. I kept him in a quarantine tank for 2-weeks, but honestly the entire procedure was a success, I don't think the little guy would've made it without it.
He eventually returned to his tank, and everything was back to normal. Unfortunately, most of his tail did not grow back, but it didn't impede with his health and was still able to swim like normal! Sunny continued to live a happy betta life for 6 more months. Unfortunately, around the 6-month period, a second tumor appeared near the location of the first one. This time he did not have a tail fin, so it actually grew on his body so I could not easily remove it. It definitely developed much faster than the first one. Since I could not remove it, I decided to let him live happily. If it popped and went away perfect, if not I would leave him alone until he shows signs of pain then I would humanely euthanize him. While that never happened and he kept being his playful self, one day I woke up and found him dead on the spot where he slept. I was just happy he did not suffer and was in a better place.
I say this to say this was my experience, but you should not panic. If it is a tumor or lymphocystis there are also many testimonies that I heard of where fish were able to beat it and live for plenty more years! Unfortunately, I believe Sunny had bad genetics and that is why it came back. I would suggest to monitor your fish and ensure his tank has the optimal conditions and low stress levels to prevent any other illness that may pile on like the issue I had with fin rot. Also if you ever do decide that you may have to remove it, please do optimal research so you know exactly what it is you are doing. I wish I could provide an exact solution, but unfortunately with this kind of condition to comes down to monitoring and reacting accordantly. If you have any more questions I would be more than happy to answer the best I can.
Foo the Flowerhorn's Video on Tumor Removal
My post
