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How to diagnose canine anal sac problems
Locate your dog's anal sacs.
Look for two sacs on either side of your dog's anus, at the " twenty past eight " position on a clock face. The sacs should each be the size of a small grape and sit just underneath the skin.
Your dog's anal sacs drain out onto his feces through small ducts. When your dog needs to toilet, the squeezing action forces a few drops of the smelly secretion out of the sacs and onto each bowel movement.