Fish Have Red Bumps On Lower Jaw

[MewMew42]

for the past few days Ive noticed that my neon rainbowfish has had a red bump on his lower aw, but isnt actung any differently

now today ive seen that my yoyo loach has an advanced form of this his mouth is open and the bump is rather swollen....

what does it sounds like? what can I do? should i put him to sleep?

 

[nosoup4you]

Bacterial mouthrot, get some antibiotics, keep the water clean.