Cotton mouth/fin rot HELP

[Comfortbo]

while doing a water change I notice this on my one loach I think I know what it is but not sure so need help to help the loach. My water is spot on nothing has changed in the tank I have pics attached input would be great. Ty UGH won't let me post pics send me a pm and I can send the pics that way I hope. White around the mouth, fins in rough shape, and looks like he's blind in one eye.