Anal Sac Disease in Dogs

Dogs have two anal sacs on each side of the anus, at about the five and seven o’clock positions (in reference to the circumference of the anus).  Problems with the anal sacs are extremely common in small animals, especially dogs.  Anal sac disease is classified into three different types:

  1. Impaction
  2. Inflammation (sacculitis)
  3. Abscesses

The anal sacs are related to the same scent sacs that a skunk has.  The skunk uses his for protection.  Dogs don’t get the mileage out of their anal sacs that skunks do.  In dogs, the anal sacs are more than likely used in territorial marking.  It is also thought that dogs use anal sacs to identify one another, hence the reason dogs greet one another by sniffing each others rears.

All breeds of dogs can be affected with anal sac disorders, although small toy breeds of dogs are more predisposed.  It is very common in miniature poodles, toy poodles, and Chihuahuas.  But don’t think large dog breeds are excluded.  I used to see anal sac problems a lot in Labrador Retrievers and other large dogs.

The anal sacs are usually emptied during defecation which normally puts rectal pressure on the sacs.  Anal sac secretions are normally liquid and brownish-yellow in color.  When they become impacted, the secretions often turn to a thicker creamy yellowish-brown color.  The secretions have a characteristic foul odor (once you smell it, you’ll never forget it).  When animals become frightened, the sacs can naturally empty when the animal tightens or contracts its anal sphincter.  That is why some dogs (especially the nervous breeds) will naturally “express” their sacs while on the examination table at the veterinary clinic or at the groomer.  This is why groomers often will automatically manually express the dog’s anal sacs before bathing the dog.

Signs of Anal Sac Disease

An animal with anal sac disease will often show some discomfort.  They will often scoot on their rear across the carpet or ground.  Discomfort will also manifest itself as chewing, licking, or biting the perineal area, or the animal turning around suddenly and looking towards the perineum as if it were pinched or stung on the rear.  Some dogs with anal sac disease will chase their tail.  Sometimes fecal tenesmus is seen (straining to defecate).  You will often see redness (erythema) in the perineal area and sometimes there will be self-induced excoriation.  Often there will be a foul-smelling discharge if there is an abscess.  There are often behavioral changes.  I used to hear some very strange things about anal sacs while practicing.  One client told me that she could always tell when it was time to have her dogs anal sacs expressed as the dog would quit using stairs.  She would bring the dog in, I would express the impacted anal sacs and presto, the dog would start using the stairs again.  Yes, that’s very strange behavior.


Impaction occurs when the sacs don’t normally empty on their own.  It usually occurs bilaterally (both sacs).  The sacs are distended and mildly painful on palpation.  Causes for impaction can be chronic soft stools or diarrhea, abnormally small anal sac duct openings, excessive glandular secretions, and poor muscle tone (usually seen in obese dogs).  When the anal sac secretions are retained, it can lead to infection and abscessation.  Impaction is treated by manually emptying the sacs.  The contents are usually thick and pasty and dark brown or grayish in color.

Inflammation (sacculitis)

There is usually moderate to severe anal pain and evidence of scooting with sacculitis. The secretions are often pus or blood-tinged.  The treatment is to express the contents of the sacs and instill an antibiotic/cortisone preparation into the infected sacs via the duct openings. I usually give the animal an injection of a broad spectrum antibiotic and prescribe an oral antibiotic for several days.  I like to re-express and pack the sacs again in 3-5 days.


Anal sac abscesses are usually unilateral (occur on one side).  There will usually be evidence of swelling of the anal sac and surrounding tissues.  The skin over the anal sac usually starts out as red in color and progresses to a deep purple.  This condition is painful to say the least.  The dog is often lethargic, running a fever and not eating.  Sometimes an abscessed anal sac will rupture on its own.  There will usually be a reddish-brown exudate and pain but usually when the sac ruptures, some of the pain will be alleviated.  Treatment is to lance the abscess and keep it open by flushing.  I use dilute peroxide or a dilute povidone-iodine solution to flush.  The dog should be put on a broad spectrum antibiotic.

In my experience, anal sac abscesses tend to be recurrent.   If this is the case, surgery to have the anal sacs removed is often recommended.

Emptying the anal sacs

As a veterinarian, I expressed a lot of anal sacs while practicing.  I never minded doing it in the least.  It is a very common problem and something we see almost every day.  I have no problem with teaching a client how to express their dog’s anal sacs at home to save them money.  I’m more than happy to do that but I will warn you, it’s not a job for the squeamish!  And I might also add, it’s not a pleasant thing to do in the first trimester of pregnancy, especially if you are suffering from morning sickness.  I found some clients are willing to learn how to express anal sacs and some don’t want any part of it.  And that’s fine.

The secretions are very foul-smelling and once on your hands or clothes, it’s hard to remove (it has to wear off and the smell doesn’t easily go away).  Therefore I recommend doing this procedure outside if possible.  Also, I don’t recommend wearing your nicest clothes when expressing anal sacs.  Believe me when I say you DO NOT want to get these secretions on your clothes, your carpet, or your curtains.  Wear disposable gloves (you can buy these at most grocery or drug stores).  I tear off a piece of roll cotton when I express the sacs because it is very absorbent, but folded paper towels or Kleenex are fine to use too.

It may take you a while to learn how to do this.  I used to tell clients it is like learning to ride a bike or milk a cow.  It’s difficult to get the hang of it at first, but once you do, you will soon become a pro.

This diagram shows a normal left anal sac and a ruptured right anal sac. Photo Credit:

This diagram shows a normal left anal sac and a ruptured right anal sac.
Photo Credit:

Grab the base of the dog’s tail and raise the tail while gently pulling back on the tail.  This will cause the anal sacs to “pooch out.”  You will usually see the distended sacs at about the 5 and 7 o’clock position (with respect to the anal opening).  Place the cotton (or paper towel or Kleenex) over the sacs with your other hand and with your thumb and forefinger, come behind the sacs and push in and squeeze.  It’s basically a milking action where you are milking the secretions out of the sacs.  Hint:  Keep your mouth closed while doing this procedure. 🙂 You will notice a foul odor and usually see the brownish-yellow secretions on your cotton when you have successfully expressed the sacs.  Repeat the process until you no longer get anything out.  You can clean the anal area with peroxide when you are done.  If it’s been a particularly messy expression, wash the perineal area with warm water and shampoo.

Sometimes when the sacs are infected or abscessed, they may be obstructed and external expression is not successful.  In that case you must express the sacs internally by inserting a lubricated gloved finger into the anus and applying pressure to the sac from the inside.

Cats can have anal sac disorders although it is uncommon.  When cats do have problems with their anal sacs, it is usually impaction.

Gail ♥

About Gail

I am a wife, mother, sister, aunt, friend, veterinarian, and wanna be writer. I love nature and animals of all kinds, music, cooking, and spending time with my family.
This entry was posted in Animals, dogs, Veterinary Medicine and tagged , , , , , , . Bookmark the permalink.

2 Responses to Anal Sac Disease in Dogs

  1. Jaye says:

    Hi Gail. That sure brings back memories for me (and many, many vet visits)….My beloved basset hound (Harvey) had recurrent problems (and a few or infections) with his anal glands through his life, and I could never “express” them myself and he would have nothing to do with my amateur hands go near him for that…..Great information! Thanks, Jaye

    • Gail says:

      Thank you for reading. I remember learning myself to express anal sacs and wondering if I would EVER get the hang of it. It’s particularly hard if you don’t have someone to help hold the dog. Yes, I imagine you had many vet visits! Some dogs have to have their sacs expressed every 2-4 weeks! Thanks for stopping by!

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