Betta growth on head by eye

Question
I have had my betta in a 5 gallon tank all by itslef with some sort of rotating wheel on top where water gets sucked up by a little black tube. I obviously don't know much about my tank.   It was a whole set (tank, filter, light) that I got at Petco all together.  I change the water once a month and I feed him every day just before bedabout 3-4 little pellets of betta food.  I got him about 1.5 years ago and I have not had any problems- at all... until recently.  He very suddenly got a growth on his head, over his mouth and under his left eye.  It actually sticks up off his body and almost looks like the growth itself is coming off by falling apart- like an open raised sore or something.  I'm not sure if this makes any sense as I dont know how to describe it very well.  I was hoping you could tell me hat is this, is this treatable and how?

Answer
Hi Risa;

It could be a bacterial infection but it's really hard to say. Fish can also develop warts, tumors, abscesses, etc. You could try using an antibiotic such as "Maracyn" or "Maracyn Two". They are both available at most fish stores. He's an old little guy so he may not be as strong as he was when he was younger. Bettas typically live to be 2 or 3 years old and are already almost a year old when we buy them. Change 25% of his water every week to help keep him stronger and keep his water chemistry more consistent. All fish really need a 25% weekly change anyway. He will be better able to fight off diseases and infections that way too. Fresh water is the cheapest and best prevention and treatment there is.

I hope he feels better soon...

At Your Service;
Chris Robbins