Have you ever noticed a musky skunk like smell emanating from your dog? It's entirely possible that your dog may have impacted anal glands or may have discharged the anal glands. The anal sacs are located on each side of the anus, just under the skin. They open to the outside by tiny passageways or ducts. Glands within the anal sacs produce a dark, foul-smelling substance. The sacs normally empty as the animal has a bowel movement. Their purpose is unknown although one theory suggests that they were once used to mark territory.
For many reasons, sometimes these tear-shaped glands get blocked. This means that while more and more liquid is produced, none is being expressed into your dog's stools. Signs of blocked anal glands include butt scooting, bloody stools, strong odor or a swollen anus.
You can express your dog's anal glands but many people find this distasteful. I wear latex gloves and am very careful when I clean out the anal glands. It isn't my favorite job for sure! Whatever you do, I would advise not getting any of the anal sac fluid on your clothes or hands. Vets regularly get sprayed with the stuff and it is totally nasty.