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Healthy Dogs

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Anal Sac Disease in Dogs

If you’ve seen your dog scooting across the room on his bottom, it could be a sign of anal sac disease.

Dogs have two small pouches on either side of their anus. They make a smelly, oily, brown fluid that dogs use to identify each other and mark their territory. It’s why they often sniff each other’s behinds.    

Anal sac disease begins as an uncomfortable impaction and can progress to an infection or abscess.


  • Scooting
  • Licking or biting his rear end
  • A bad smell
  • Constipation or pain when pooping/sitting

Stages of Anal Sac Disease

Normally, when a dog poops, the fluid in his anal sacs is squeezed out, too. It’s when they aren’t completely emptied that problems develop. The fluid inside can become so dry and thick that it plugs up the openings. This is called impaction.

Thankfully, impacted sacs are easy to treat. The glands can be gently emptied, or expressed, with your fingers. You may have to do this regularly, and to save a trip, your vet can show you how.

If your dog repeatedly has impactions, you vet may suggest adding more fiber to his diet. This increases the size of his poop, which puts more pressure on the sacs to empty naturally.

If your dog doesn't have a problem, there is no need for you to empty his sacs.

Left untreated, the impaction will turn into an infection. Look for yellow or bloody pus oozing from his sacs. This painful condition can cause your dog to act fearful or angry. Your vet will wash out the sacs and give your dog antibiotics.  

An untreated infection will develop into an abscess (a swollen, tender mass of puss) and could break open. Your vet will open and drain the abscess and usually prescribe antibiotics and anti-inflammatory drugs. Daily warm compresses can help, too.

If your dog keeps having problems, your vet may want to remove his anal sacs with surgery. It’s a simple procedure, but can result in complications like fecal incontinence (when his poop leaks uncontrollably).


Put your dog on a healthy diet and make sure he gets plenty of exercise. Small, obese dogs are at the highest risk of anal sac disease. Also, if you dog has problems with his anal sacs, have your vet check them at every checkup.

WebMD Veterinary Reference

Reviewed by Amy Flowers, DVM on November 21, 2014

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