When I came home from work tonight, I notice my dog licking himself a lot. I looked and the tip of his penis is swollen

It is swollen with what looks like a fluid filled pocket. Kinda looks like a boil. Because of this, its not retracting like normal. I would like some other opinions on whether this should require an emergency call or if he should be ok until morning. If anybody else has had this happen to a pet would be even more helpful, thank you.

Asked by Member 1144675 on Dec 10th 2012 in Emergencies & First Aid