My dog has a skin rash that started on her paws. It looks like blood blisters, the skin is thin and when i drain them, blood and some oil/ clear liquid comes out. some times it is green like puss and hairs shoot out. The paws are swollen and very red. their is some kind of scab, thick brown paste that builds up in the webbing. I have taken her to the vet and they can not figure it out.