Hardly a subject for polite conversation but an important one nonetheless, is dogs’ anal glands. Technically they’re not glands, however they’re commonly referred to as glands and they are repositories of some revolting smelling substance. They are two small sacs that continually produce an oily material - semi-liquid - from the cells with which they’re lined.


Why do dogs have them?

The first question that comes to mind upon learning about these rather unpleasant parts of the canine anatomy is, why dogs have them and what is their purpose? Well… these little nasties are essentially scent “glands”. They are a pair of pockets that are situated between the layers of muscle that form the rectum, and there is one on either side of the anus at approximately the four o’clock and eight o’clock positions. They empty via a short, narrow duct to a point near the inside edge of the anus.


Lined with numerous oil and sweat glands, the secretion from them is a brownish fluid with a strong and offensive odour. When they’re working as intended, each time a dog defecates they are naturally expressed. Dogs use them to mark their territory and leave a “signal” for other dogs that come across their excrement.


Not only dogs have them

Most dog owners aren’t aware that they exist but in fact, cats, skunks, and other mammals also have them. Fortunately, humans don’t, even though they get haemorrhoids, something that dog’s do not. There are many theories of why some animals have anal sacs and one, in addition to them being used for a powerful “stay away” signal, is that their contents when excreted with the passing stool or by sphincter muscle contraction, lubricates hard stools, thereby making passage easier.


If they’re so unpleasant, why are talking about them?

The reason anal sacs come to the attention of vets and pet owners, is because dogs sometimes suffer from anal sac disorders, and whilst the exact number is unknown it’s thought to be at least 10% of dogs. They become a problem because some dogs' anal sacs produce a thicker material which is more likely to become impacted because they’re unable to express the semi-solid material through the narrow duct. This can lead the sac to become infected, causing pain and inflammation.


Infected anal sacs become abscessed if not treated, and rupture through the dog’s skin is possible once the pressure within the abscessed sac builds to a high level.  The abscesses can consequently require surgical repair, and the dog will usually require pain medication and antibiotics. Dogs that suffer recurrent and chronic skin inflammation conditions will often have recurrent problems with their anal sacs.


How to tell whether your dog has an anal sac problem

The thought that their dog might have a problem with their anal sacs will never occur to most owners, however there are often a variety of signs that dogs have problems and some are more obvious than others. If these signs appear repeatedly, or if your dog has a history of anal sac problems, then it’s time for a visit to the vet:


  • Dragging bottoms along the ground (or indoors on surfaces such as carpets), also known as “scooting”
  • Excessive anus licking
  • Difficulty when defecating which may be indicated by straining or vocalising
  • Swelling under the skin next to the anus, or a bump
  • Blood and/or puss on stools
  • Blood and/or puss on bedding, carpets, or surfaces on which they’ve been laying, such as your lap


Is there anything that increases susceptibility to problems?

There are a number of things that can increase your dog’s chance of anal sac problems and they include:



Some dogs are born with particularly narrow channels leading from the sacs to the edge of the anus. These increase the susceptibility of obstruction of the flow of anal sac material. Infections, allergies, trauma, and inflammation can also cause compression or obstruction of these naturally narrow channels.


The relevance of age and breed

While there is no gender or age predisposition to anal sac pathology, infections and impactions are more likely to be experienced by smaller breeds such as Toy and Miniature Poodles and Chihuahuas. Beagles, Basset Hounds and Cocker Spaniels are also more likely to experience problems than larger breeds.


Something that can also lead to problems occurs at the groomer’s. Anal sac expressions that may be performed during routine grooming can cause future problems because of the squeezing that’s done to express the secretions. It can lead to scar tissue formation which contributes to further narrowing of already narrowed anal sac ducts.


What can be done to help?

The starting point to help a dog suffering frequent anal sac problems is to engage the assistance of a vet. They’ll help you to determine and manage the underlying cause(s) of recurring problems.


Being overweight or obese can be a contributory factor, therefore it’s important to get your dog to a healthy weight. There are numerous health care issues that can result from obesity in addition to anal sac issues. Excess body weight is often caused by overfeeding and/or inadequate exercise. Your vet will also determine whether hypothyroidism or Cushing’s disease is involved as part of the problem.


Increasing fibre in dogs’ diets can sometimes help. Pumpkin, psyllium fibre supplement, or veterinary prescription and over-the-counter high-fibre diets may assist.


Food hypersensitivity can increase the chances of dogs suffering from anal sac problems, therefore a hypoallergenic diet will help to alleviate chronic anal sac issues in some dogs.

Your vet can help you choose an appropriate diet for your dog.


Is there a permanent cure?

Dogs that have frequent anal sac problems may benefit from having them removed in a surgical procedure called an anal sacculectomy. The procedure isn’t without potential complications most notable of which is nerve and muscle damage, and it can be costly. It is therefore usually regarded as a last resort rather than first line treatment. It will sometimes be performed by general veterinary practitioners, but may also be referred to a surgeon in order to minimise the risks of complications. As with any surgery make sure you discuss the pros and cons with your vet

Don’t hesitate in getting help if you suspect problems

Left untreated anal sac impactions, infections and abscesses, can cause considerable pain and discomfort to your dog. It is therefore imperative that you seek veterinary advice if your dog displays any discomfort down “that end”. Your vet can diagnose the cause and help make your dog more comfortable, and work with you to minimise the risk of recurrence. It’s important to get the bottom of your dog’s health care issues, whatever they may be, including problematic junk in their trunks!