All About Your Dog’s Anal Sacs Learn How Anal Sacs Work and How to Identify A Problem

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In this article, we will explore the location and function of your dog’s anal sacs or anal glands, as well as what can go wrong, such as anal sac impaction, abscess and infection, anal sac disease, and how to identify symptoms and treat problems.

This article is not for the squeamish! It’s a topic that many pet parents wish they could avoid, but the reality is that understanding the function of your dog’s anal sacs and the potential complications is important.

The anal sacs -- also known as anal glands -- are two small repositories located around your dog’s anus that continually produce a foul-smelling substance. The odor of that substance is what identifies your dog and marks their stool as a way to establish territory. This is why rather than shaking paws when two dogs meet, they smell each other’s rear ends.

Here we will review what you need to know about your dog’s anal sacs and anal sac disease.

How Do Anal Sacs Work?

If looking at your dog’s anus straight on, the anal sacs are located between the internal and external anal sphincter muscles at 4 o’clock and 8 o’clock. The sacs are lined with sebaceous glands (oil glands) and apocrine glands (sweat glands) that produce a somewhat oily, brownish in color, and awful smelling substance. The sacs are connected to the outside by small ducts that open just inside of the anus.

The anal sacs are often emptied by the pressure caused by a large, firm stool. They can also empty if a dog is afraid or upset and responds with forceful sphincter contractions.

In some dogs, the glands do not empty regularly as they should, which can lead to a blocked accumulation of secretions known as impaction.

Anal Sac Impaction: Causes, Symptoms, and Treatment

Anal sac impaction occurs when the sacs do not empty and secretions accumulate. This can happen if a dog is passing soft or small stools that do not create enough pressure to empty the sacs. It can also occur as a result of anal sphincter muscle dysfunction or if the openings of the anal sacs are blocked by thick, semi-solid secretions (which, for unknown reasons, some dogs are prone to producing).

If your dog’s anal sacs are impacted, they will be distended and tender. In addition, your dog may “scoot,” chase their tail, and lick or bite their rear end. Impactions are most common in small-breed dogs and overweight dogs, and if left untreated can lead to infection, abscess, and ultimately rupture. This whole cycle is what is referred to as anal sac disease.

Anal sac impaction is treated by manually expressing -- or emptying -- the anal glands. Your veterinarian can do this or can show you how to do it at home. If your dog has recurrent impactions, it is a good idea to learn how to do it and manually empty the sacs on a schedule set by your veterinarian. Your veterinarian may also prescribe a high-fiber diet to increase the size and firmness of your dog’s stools.

How to Express Your Dog’s Anal Sacs

Sounds pleasant, doesn’t it? Once you get used to it, emptying your dog’s anal sacs becomes just as routine as brushing their teeth or trimming their nails.

We’ll provide some instruction here, but you should consult your veterinarian before attempting to express your dog’s anal sacs for the first time.

1. Put on latex or plastic surgical gloves. (Trust us: you don’t want to get this substance on your hands!)

2. Raise your dog’s tail and locate the openings at 4 o’clock and 8 o’clock.

3. If the anal sacs are full, they will feel like small, hard lumps.

4. Take the skin surrounding the sacs between your thumb and forefinger and squeeze. If the anal sac is impacted, you may need to put your forefinger inside of the anal canal and have the thumb on the outside.

5. The secreted substance will smell very strong, and should be liquid and brownish in color. If the substance is pus-like, yellow, or bloody, the anal sacs may be infected, and you should contact your veterinarian.

6. To clean up, wipe your dog’s rear end with a damp cloth or spray with a hose.

Anal Sac Infection: Symptoms and Treatment

Anal sac infection is a potential complication of anal sac impaction. The symptoms of an anal sac infection include painful swelling of the anus, pus-like, yellow, or bloody discharge, discomfort when defecating, and “scooting,” licking, or biting the rear end.

An anal sac infection will be treated by your veterinarian. They will manually empty the sacs and place an antibiotic directly into the sac. They may also prescribe your dog with an oral antibiotic. Dogs with recurrent anal sac infections sometimes have their anal sacs surgically removed.

Anal Sac Abscess: Symptoms and Treatment

Anal sac abscesses can occur when there is a severe anal sac infection. If your dog has an anal sac abscess, they will show the same symptoms of anal sac infection and may also have a fever. An abscess will begin as red and eventually turn purplish, and may ultimately rupture through the skin. The substance that comes out will likely be greenish yellow or bloody.

If you suspect that your dog has an abscess, you should contact your veterinarian right away. If the abscess has not already ruptured, your veterinarian will be able to lance it, clean it, and then place your dog on an oral antibiotic. If the abscess has already ruptured, treatment is more intensive and may include surgery to clean the sacs, removed affect tissues, and place a drain to ensure that fluids drain normally.

In these cases, your veterinarian may also suggest removing the anal sacs at a later date.

Anal Sacs Problems In Dogs (And Cats)

The reason behind why some animals have anal sacs are still a topic of wide debate. There has been much research into the matter and many speculations. It’s a tricky area of your pet’s body. They are also often known as anal glands although technically they do not really have a glandular structure. Many pet owners are concerned about the problems that might occur in this undiscovered area of their pet’s body. The anal sacs secrete an oily liquid-like substance which is stored inside the sac.Most veterinarians and scientists still have no clue as to why this liquid-like substance is excreted. You might find yourself confused and concerned if your vet tells you that your dog has a problem with his anal sacs. Anal sacs are likely to be infected as it is located right next to the dirtiest part of your dog’s body.

Treating Anal Sac Infections.

Anal tract infections are fairly easy to treat and diagnose. Your vet will first examine your dog and if he finds a swollen or inflamed spot next to your dog’s anus, he will then recommend treatment. The infection causes an abscess that appears on the dog’s skin. The abscess will look like it is almost ready to pop or breakthrough. To treat this condition, your vet will open the abscess in order to drain the infection from the infected anal sac. He will then flush the sac and check for infection in the other sac. If he finds that everything is as it should be, he will put your dog on antibiotics and simply send him home to rest.

What Exactly Are These Anal Sacs?

There have only ever been theories as to why some animals (cats, dogs, skunks etc.) have these sacs. One theory is that the liquid-like substance that is secreted by these sacs along with the stool acts as a territory marker due to its strong smell. Not unlike how we humans hang up ‘No trespassing’ signs to mark our property. Another theory is that the substance that’s secreted by the anal sac makes the passage of the stool easier by lubricating it. Just like how humans can get hemorrhoids, dogs get anal sac infections.

What Causes The Problems With The Anal Sac?

As the anal sac is an unusual body part, there aren’t specifics to what causes the disorders. The dysfunction of the muscles of the anal sphincter, sacs that appear enlarged due to under-compression by the muscles of the anal sphincter, hypersecretion of the liquid-like substance from the lining of the anal sac, and ducts of the anal sac that may be obstructed or constricted, are all predisposing circumstances that may cause problems with the anal sac.

How Do You Tell If Your Pet Has This Problem?

Only 12% of dogs experience disorders concerning the anal sac. There is an 88% chance that you will never even hear the term ‘anal sac’ from your vet. But if you are part of the unfortunate 12%, there are a few simple ways to recognize this infection. If your dog shows any kind of discomfort while passing stool or frequently turns and tries to bite his rear end, you might want to make an appointment with your veterinarian.

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