I’m not an expert, others will give more detailed replies, but I had something similar with my male and it was caused by over feeding . The whole ’feed what they can eat in a few minutes‘ does not apply to Bettas!I am a bit new to aquariums, and not sure if this is normal or not....
I do tend to over feed my fish… I’ll try to see her poop.It can be :
• overfeeding
• constipation
• internal parasites
How is her poop ?
What do you feed her and how much ?
She seems pretty active, what would be other signs of kidney failure?I'd say kidneyfailure.
Lookat where kidney is placed. Seems improbable to me.I'd say kidneyfailure.
I guess you're right