My cat has this dark red whelt on his tongue and the front of his mouth is swollen, he can't close his mouth and he's drooling excessivly, now I know he should see a vet but we can't get in right away, He came home like this from running away, he is not an outdoor cat. please help!

JudyKayTee

It could be anything from a problem with his jaw to poisoning to some other type of injury - I think you have to get him to a Vet if for no other reason than he's most probably in a lot of pain and most likely cannot eat or drink.

Cats dehydrate very quickly.