looks like growth

[originalweaver]

my betta has what looks like a growth just behind his breathing fin, he is still swimming on his side some but can swim normal at times. what could this growth thing be, he still dosen't seem to be eating but is quite active

[Falina]

By breathing fin do you man gill?

What does the growth look like? A tumour? Cotton wool? Something else?

What are your water parameters? Are there any other fish in the tank?

We'll need a bit more info before we can help I'm afraid.

If you have a photo that would be the most helpful thing for us.