Act quickly and reasearch Columnaris for additional info. Keep us posted on results. Good luck I hope you save it.
He passed last night. Thanks for your help, I should have reached out earlier.
Act quickly and reasearch Columnaris for additional info. Keep us posted on results. Good luck I hope you save it.

This is Columnaris aka Flexibacter, Mouth-Rot/fungas ect.
Do not increase the temperature!
This is one instance where you want to drop the temp to around 74-75F. This bacteria grows poorly below 76F
Do a large 75% water change and gravel vacuming. Kanacyn (kanamycin) is a great choice or use both Maracyn and Maracyn 2 together but they must be used together. This will kill your fish if you don't act quickly. Treat the whole tank. Follow the directions on any medication you use. These will kill your bio-filter so you must do frequent water changes while treating and afterwards till they reestablish.
Your fish can go a few weeks without eating, treatment is key here.