My dog has a thing on her mouth that oozes blood what is it and it's blood red
she's 15 and a half
She's probably getting pretty old, you should take her to the vet to make sure everything is going ok with her.
I would take her to the vet
Might be a blood blister.
It could be an ingrown hair that's getting infected or sunburn, I would see a vet or at least call one.