Should I euthanize?

Hey guys. I'm faced with a difficult decision here. I have a fish in my 45g that is very old and has a crooked spine and abrasions on its side. He's some type of tetra I was given a few years ago. These are symptoms of fish TB, and I don't want it to spread. Should I euthanize this guy before the condition spreads to other fish, or will the others be ok if I let whatever's ailing him take its course? He seems to be acting fine, but he's just crooked and has some abrasions.


Thanks.

He's been like this for a few months now. He's only been with other fish for the past 2 weeks. The abrasions are brown and it's almost like his scales or maybe his inside is rotting or something. I don't have any pictures handy.

Well he died, so he's been removed and disposed of.