i had this happen to Rosi, and she was having the dryheaves, she was salvating teeth clenched, shivering...trying to poop but couldn as poop was stuck to her butt and crying, scared the heck out of me, switched her to many times with diffrent dogfoods had to take her to the emergency clinic at 2am where they had to shave her butt and clean her out and hydrade her, i felt soo bad... next day she had a very raw butt , had to give her 1/4 of a baby asprin forced vaseline in her mouth and used preperation h on her butt , then used the towelettes for a few days, that was a lesson i wont forget, i felt like such a bad mommy, thanks to Kimberly's help i learned alot...please call the vet ! Rosi was fine couple days later, and she got a new nickname :Barebutt
as i make shure groomer keeps it that way !