My lab/shep mix seemed to have a small swelling around his rear, a bit below and to the left of his anus that we noticed on Saturday. I thought to keep an eye on it because he seemed content, was pooping and didn’t appear to be in any pain. Today it was more swollen, but as it is Sunday, I was planning on calling the vet tomorrow. He pooped a while ago, when we were outside playing in the snow and then when we came inside. When he came in, he licked himself and then the swollen area sort of popped, like a big pimple, and has been draining puss/blood at first but now it has stopped and only seems to be draining blood when he licks himself. I still plan on calling the vet tomorrow, but should I be more concerned and take him to the emergency vet, even in this bad weather?