Skin problem with tiger salamander

[natureboyfts]

Hey everyone,

I noticed 1 of my tiger salamanders has this weird looking cut on his skin.

I house him with another tiger salamander whose a female, they seem to get along well but now I'm curious if she bite him or if maybe he has developed some weird skin disease or condition?

Any ideas?

 

[Asevernnnn]

The substrate could have caused that, that substrate can probably cut that salamander all over the place. Plus these are mole salamanders, they will try to dig, which could cause more wounds. I would switch to a coconut fibre substrate and someone else might have advise on treating it