Beta fish has white lump on back

Question
Our 6 yr old daughter got a beta fish at the end of May. So far he - named Erica - has been doing well in his 10 gal. tank with friends (4 neon & 2 catfish). The tank is filtered & heated. This past week we've noticed a lump or bulge on his back (the top side) in front of his top fin. It's white with grey in color. Other than this lump, he seems to be doing just fine. Is this some sort of tumor & should we be concerned with the other fishes well being?

Thanks in advance for any and all assistance!  

Answer
Hi Katie;

A Male Betta named "Erica"; that's cute! I guess if you are a six year old any name you want is what you get. ;-)

It may be a tumor or infection of some kind. I can't say that it is contagious, because I'm not sure what is causing it. Hard for me to tell without actually seeing him. You could separate him but it would be hard to keep him warm. I would watch to see if it changes. It still could be a tumor or something as well. Fish can even develop 'warts'.

You might want to invest in another small tank (5 gallon) with a heater just to keep him safe and help him heal. We call this a "Hospital Tank". If you see the lump get bigger or worse, I would definately separate him and use a medicine called "Maracyn 2". It absorbs inside the fish to treat bacterial infections. Others treat only the outside of the fish and I don't think they would help him really. Make a 50% water change in the hospital tank every day. Once he gets well and the extra tank is no longer needed you can store it for other emergencies.

Here is more about hospital tanks, also used for quarantine of new fish;
http://www.uniquaria.com/articles/ht.html
http://www.drhelm.com/aquarium/quarantine.html
http://www.aquatic-hobbyist.com/profiles/misc/qtank.html

Hope he gets better soon......

At Your Service;
Chris Robbins