Is this columnaris?

[WetPetMum]

I noticed this on my Silvertip three days ago.. not sure what it is or how he got it?
If it is cotton mouth how should I treat him please?

 

[GaryE]

I don't see anything cottony. He has hurt his mouth, but for now, I would keep the water clean and see if it spreads or heals. A photo gives very limited info, but I would expect it to heal.

 

[WetPetMum]

I don't see anything cottony. He has hurt his mouth, but for now, I would keep the water clean and see if it spreads or heals. A photo gives very limited info, but I would expect it to heal.

Thanks Gary I shall keep an eye on him