Anal Glands in Dogs

16 February 2022

This article is written by one of Pet Circle's in house veterinarians, Dr Elise Barry BVSc.

Ever wondered why your dog loves to sniff another dog's back end? Well the answer is because of the anal sacs. Dogs have two special sacs found inside their bottom called the anal glands. These sacs contain a thick, oily and fishy-scented substance with a smell that is completely unique to your dog.


Why does a dog have anal glands?

Causes of anal gland issues in dogs

Symptoms of anal gland issues

Treatment of anal gland issues in dogs

Further Reading

Why does a dog have anal glands?

The substance produced by the anal glands serves an important function. The contents produced by these glands are regularly expelled when your dog defecates. They are specific to each individual dog and are influenced by their diet and hormone levels. This substance is a wealth of knowledge, whereby a dog can determine if they've met before, identify the other dog's sex, mood and even any illnesses they may be suffering from. So much information from one smelly substance!

The anal glands are also emptied and that wonderful fishy-scented substance is released when your dog is scared or very excited, similar to the defence mechanism utilised by the skunk. This is the reason behind smelling that pungent smell perhaps during car rides, thunder storms or even trips to the vet - any situation which causes your dog to be extremely excited, stressed or anxious.

Causes of anal gland issues in dogs

A dog's anal glands should empty when they defecate - the stool pushes against the gland, expressing the secretions through the anal gland duct and into the rectum. This may not occur for a number of reasons.

Blocked anal glands

The anal gland duct may become blocked due to thicker than normal secretions (often due to failure of the gland to empty normally), or anatomical factors such as an unusually small duct system. This may lead to inflammation and infection of the anal gland (the anal secretions sitting in the gland are a lovely place for bacteria to grow!).

Anal gland impaction

Anal gland impaction occurs when the contents of the anal gland accumulate, and are not released normally from the gland. This can occur due to anal duct obstruction, gland inflammation, infection or anal gland tumours, as well as chronic diarrhoea, weakness in the anal muscles, obesity and constipation.

Infected anal glands

Anal gland inflammation and infection can occur with or without duct obstruction, including due to underlying medical conditions such as hormonal disease or allergic skin disease, or incorrect or too frequent manual expression of the glands.

Inflammation, infection and impaction can cause distension of the anal gland, leading to pain and potentially abcessation and rupture of the gland.

Anal gland cancer

In some cases, there may be a tumour affecting the gland, causing distension, swelling and pain.

Symptoms of anal gland issues


The most common sign of anal gland issues is bum scooting. Everyone's seen a dog sliding happily along on their backside - usually on the carpet! This behaviour is unmistakeable, though it is not always associated with anal gland issues. Other reasons for scooting include flea allergy, allergic skin disease or intestinal worms, particularly tapeworm.

Anal gland smell

The pungent smell of the anal gland secretions is one you don't easily forget. If the anal gland ducts are not completely blocked, you may smell the fishy-scent, especially if the glands are over-producing their secretions due to irritation or infection.

Anal gland swelling

You might also notice a swelling and perhaps redness around your dogs anus (at around the 5 o'clock and 7 o'clock position if you imagine the anus as a clock face). Some dogs may lick or chew at their backside due to the pain associated with anal gland issues, and as an attempt to relieve the discomfort.

Ruptured anal glands

In cases where the anal sac has ruptured, you may notice a wound and/or secretions (either dried or wet) around your dog's backside.

Treatment of anal gland issues in dogs

The treatment of anal gland issues depends on the cause, and stage of disease. Most anal gland issues can be managed medically, by manual expression, flushing of the anal glands, antibiotics and a dietary change. If your dog is showing any of the symptoms of anal gland issues, it is important to check in with your vet to determine the underlying cause, before attempting any home remedies.

Expressing the anal glands

To alleviate the irritation from impaction, the anal glands need to be manually expressed or emptied. Your vet clinic will be able to help with this, or even your groomer. Technique is important here, as incorrect expression can lead to further irritation and inflammation of the gland.

Medical management

Depending on the cause and stage of your dog's anal gland disease, your vet may recommend a flush and lavage of the anal glands, antibiotics and/or pain relief. In cases of abscessation of the anal glands, they may need to be lanced and drained.

High fibre diet

Adding more fibre to the diet either via a fibre supplement such as pumpkin, bran or psyllium husk, or a high fibre therapeutic diet such as Royal Canin Gastrointestinal High Fibre or Hills Prescription W/d may help to prevent impaction. The higher levels of fibre bulk up the stool volume and create greater compression of the rectal wall and anal glands as the stool passes by. This helps to express the anal glands naturally. Please note that these specialised therapeutic veterinary diets must be used only under your veterinarian's recommendation and supervision.

Anal gland surgery

In severe or frequently recurrent cases of anal gland disease, or where a tumour of the anal gland is suspected or has been diagnosed, surgery to remove the anal glands may be the most appropriate option. This surgery is not without risk though, so it is generally considered only when medical management has failed.

Recommended products for dogs with anal gland issues

*Please note these are specialised therapeutic veterinary diets and must be used only under your veterinarians recommendation and supervision.

Further Reading

Want to know more? Take a look at our other dog health articles such as:

Urinary Crystals in Pets

Which Plants are Toxic to dogs?

Can Dogs Eat Chocolate?

Premium Pet Food: Is It Worth It?

Pet Health Care: Which approach does your pet need?

Shop All Dog Supplies Now