LOL. Yogi had that happen to him right after I first got him. It just so happened that I noticed it right when we were running out the door to take him to his first vet appointment, which we were already late for!!!
I tried to cut and clean him up the best I could. I was so embarassed to take him in to the vet, not totally clean. But they were understanding and actually cleaned him up the rest of the way for me before I left!!
He went in the next day to the groomers for what they called a "sanitary cut".