Poor fella
It's so hard for me to imagine anyone that could treat any animal so poorly
Bless you for giving him a loving home
I hope that the vet can help you to make him as healthy as possible. Might want to buy some Missing Link supplement, you sprinkle it on their food and most LOVE it! You can get it at just about any pet supply store (PetSmart,PetCo, PetSupermarket) It's made a huge difference in my Luna's skin, it was horribly dry and flaking, and after a couple of weeks, it's 50% better
Keep us posted on this guy. And welcome!