Mouth rot... Please help

[Buddy]

I got Frank a week back and he's not in great condition. He is thin, he has old shed on his body and I noticed what kinda looked like old shed in the corner of his mouth. Today when I fed him roaches I got a closer look, he has mouth rot, no doubt about it. What do I do now, besides taking him to the vet? Some days ago I switched cages on him and Buddy, since he is so active I figured he would need the extra space. I read that it's highly contagious, can I expect Buddy to get it now?

[Susann]

Have you gotten a look inside the mouth to see if it goes past the lips?
If it does, and you do take him to the vet, ask if it would be a good idea to put Buddy on the treatment as well to try to prevent infection. I don't know if it works that way, if it can be prevented, but since it seems there's been a contamination.

[Buddy]

It's on the inside too, like on his row of teeth. Everything just looks like a mushy wound. I'll check with the vet if it's possible to give Buddy preventive treatment.

[Susann]

I would suggest, even though there's been contamination already, to separate the new skink from your other two. I know some would say that the contamination has already occurred so no need to separate now, but in my opinion there's no need to keep contaminating if it hasn't happened yet. You know?

[Buddy]

Yeah, but they're not in the same tank, never have been. But I switched tanks a few days ago..

[Susann]

When I bring a new skink home I go through a quarantine period (I personally do a minimum of 2 months) when they don't even go in the same room as each other without me disinfecting the surfaces they touch first. Not everybody goes to these extremes, but it is good to at least go through some time period where you have a new skink in your home for long enough for problems, if any, to manifest.

[Buddy]

Yeah, I know. I wasn't going to switch tanks but he's so active that all he tried to do was to get out of the smaller tank, ended up bleeding on the tip of his nose from rubbing it against the glass. So I had to switch them before he hurt himself more.

[Spindown]

I'd take him to the vet ASAP, mouth rot can go from bad to worse quickly.
How did you clean the tank that had the sick skink in it before you put the healthy one in?