strange hard tumor under chin

Question
We have had Pinkie for almost 2 years, he is a hairless dumbo rat. A few weeks ago we were worried because he had a large hard bump under the side of his mouth. It was so big he had a hard time eating and I had to mash all his food and give him water myself. It ended up draining and was pretty much gone except for a small black hole on it. I just noticed that it's back but smaller, it almost looks like a wild tooth that grew the wrong way but I can't be sure, his tail is also scabby and bloody, and his skin has been quite dry and flaky too. He has an appointment tomorrow at a vets. I am extra worried because he is a family pet and the three kids just lost his brother a few weeks ago. He didn't even seem sick! He just lost control of his body, was having seizures and died later that day. Considering what just happened Pinkie has to live forever, Can you help me! Please!

Answer
Well I hate to be the bringer of bad news, but Pinkie won't live forever. Of course, you know that. Pinkie is already considered a senior citizen for (what I assume is) a pet-store bred hairless rat (if he isn't and he's from a breeder, that changes his lifespan by probably a year, depending on the breeder).

The new bump under his chin may also be an abcess like the first one was, I've noticed in my own personal experience that chin abcesses tend to behave differently than bodily ones do - generally body abcesses are squishy, not hard. Then again, it COULD be a tumor. The vet will be able to confirm one way or the other for you, if he's experienced with ratties; it's a pretty simple procedure to find out.

Have his tail checked out, and ask the vet to do a skin scraping for mites.. otherwise, his dry skin is probably just a-typical hairless skin, which tends to be dry and flakey whenever we humans start getting dry and flakey.