Anal gland impaction

Anal Gland Impaction

They're not the stuff of dinner party conversations, but knowing how to spot a problem could save your dog a lot of misery.

Picture the scene. You've just washed your dog from top to tail using the finest shampoo and conditioner money can buy, but even after drying him, the same horrible fishy odour you noticed pre-groom is still lingering in your poor nostrils. Sound familiar?

'So where's it coming from?' you wonder - even though most of you have probably guessed by now that your dog's smelly anal glands are the culprits here.

What are anal glands?

Anal glands (or anal sacs) are relatively small glands found on either side of your dog's anal opening. Not present in humans, they are paired sacs located precisely just below the surface of the skin between the external and internal sphincter muscles, employed by nature to produce a particularly thick, foul smelling, oily liquid secreted by glandular tissue for identification and territory marking. This is the reason dogs smell other dogs' bottoms when they meet and greet, standing tense with tails erect to swap their own unique smells (rather like individual fingerprints).

How do dogs empty their anal glands?

Domestic animals like dogs and cats have largely lost their ability to empty these glands voluntarily - unlike the skunk's world-famous pungent defence mechanism. Your dog's anal glands may spontaneously empty just by walking around, especially under times of stress, creating a very sudden unpleasant change in his odour. Passing normal firm stools puts natural pressure on the rectum walls to empty the glands and will, to some degree, help to lubricate the anal opening in the process, making it easier for your dog to poo.

How can anal glands become impacted?

Anal glands fill for a number of reasons: most commonly when the dog's stools are soft (for example, after a few days of diarrhoea), so insufficient pressure has been exerted to empty the glands. Whenever they fail to vacate properly there's a chance of becoming impacted or, even worse, infected - a very painful condition requiring urgent veterinary treatment.

Impaction results from blockage of the duct leading from the gland to the opening, with the gland usually becoming non-painful but swollen. However, infection can result from prolonged impaction giving the glands a chance to build up nasty bacteria resulting in pain, increased swelling and, sometimes, even abscesses and fever.

How do I know if my dog may have a problem?

Under most circumstances, anal gland secretions are extremely minute, so you don't usually see or smell them - though you may notice your dog's bedding becomes a bit smelly between washes. But when you can actually smell the odour emanating from your dog's backside there may be a problem.

Your dog may happily pass through its whole life without ever having any problems with its anal glands, but not all dogs are so lucky. Normal anal gland fluid ranges from yellow to tan in colour and is watery in consistency. Impacted anal gland material is usually brown or grey, and thick with the occasional presence of blood or pus indicating infection.

Some dogs seem unable to empty their glands fully on their own, causing the glands to become impacted and uncomfortable, and the dogs to drag or 'scoot' their rear-ends along the ground (or more commonly your brand new cream-coloured carpet) in an attempt to empty them.

Other signs include licking or biting around their anal area, chasing their tail, sitting uncomfortably, or even licking paws - both front and back - in sheer frustration.

How can this be treated?

Vets will usually treat this by expression of the gland (usually far too painful in the conscious patient), antibiotics and pain relief, and even repeated flushes of the glands. Signs of severe infection might include distinct bulges just beneath the surface on either side below the anal opening, drainage from the rectum or even one or more abscesses in the immediate area.

With rare cases of recurrent infection or presence of a specific type of malignant tumour called an anal sac adrenocarcinoma, anal glands may be removed surgically by a procedure known as anal sacculectomy. The potential complications of this specialist type of surgery, however, make the operation strictly reserved for essential cases only.

Should I regularly empty my dog's anal glands to prevent this happening?

Be aware that not all dog experts agree the anal glands should be interfered with in any way - unless the dog is showing signs of a problem.   If you are concerned about anal gland impaction then speak to your local veterinarian for advice.  Applying pressure to an anal sac impaction or infection could cause the gland to rupture, and lead to bleeding and painful complications for your dog.

So if you didn't know anything about your dog's anal glands before you read this article, you probably know more than you ever thought possible now! But at least you'll be able to detect and identify any issues quickly and hopefully save your dog from the pain and discomfort of anal gland problems.

Who can I contact for further advice?

The Kennel Club is not a veterinary organisation and is unable to provide general or case specific veterinary advice.  If you have any questions regarding any of the issues discussed in this article then please contact your local veterinary practice for further information.

This article was written by Marc Abraham and was originally published in the Crufts Magazine -

Marc Abraham is a vet based in Brighton.  He regularly appears on UK television.  For more information about Marc please visit

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