Anal Glands

In the dog

All you (didn't?) want to know about anal glands*

Anal glands, or ANAL SACS, to use the correct term, are two balloon shaped sacs set on either side of the anus at about the 4 to 5 o’clock and 7 to 8 o’clock positions. They are located between the inner and outer muscle layers of the anal sphincter and the neck of the sac opens just near the inner margin of the anus. Both dogs and cats, amongst other animals, have anal sacs, but the skunk has the most developed
In our domestic pets, however, they have little function
The anal sacs are lined by apocrine and sebaceous glands, which secrete and fill the sac with a foul smelling watery-pasty fluid. The sacs are normally expressed when the dog or cat passes a motion or when the animal is highly stressed, anxious or frightened. This may be after they have been in a fight, hit by a car or just because they are picked up and put on the examination table in the veterinary clinic
Problems arise when the sac is not expressed
If the anal sac becomes too full the animal becomes very irritated and may start ‘scooting’, ie dragging its bottom along the ground. This might relieve the problem, (leaving a foul fishy smell on your carpet perhaps) but if it doesn’t, the anal area may become quite painful
This can cause constipation and behaviour changes such as the tail being kept down between the legs, biting and chewing the fur around the tail or tail chasing. If the sac continues to fill the skin next to the anus starts to die off and the now abscessed sac bursts out through the skin. Often the abscess is not noticed until a weeping, bloody and painful sore is seen under the tail
If you see your dog or cat scooting or paying undue attention to the tail area, it might have worms or some form of dermatitis around the anus, but it is highly likely to have full anal glands that need emptying
This can be done by either milking out the individual sac between the thumb and finger, with one gloved finger inside the anus or by squeezing both glands at the same time between thumb and fingers outside the anus. For both methods use gloves, lots of cotton wool or tissues covering the anus and DON”T STAND BEHIND THE DOG OR CAT when you do it. (A face full of anal gland secretion will ensure you never do it again.) Only the dedicated few will express anal sacs for their own dog or cat, so if you think your pet has this problem, come to the vets and we’ll do it for you
Small dogs are usually more prone to this problem than larger dogs, though we still see larger dogs with the problem especially if they have an allergic dermatitis and German Shepherds are particularly prone to a problem known as ‘Perianal Fistula’ where so many draining tracts open out to the skin it gains a lacy appearance. Cats rarely have a problem though overfull sacs and impactions can and do occur
Usually expression of the sacs at regular intervals can control scooting and perianal irritation, but occasionally surgery is required to remove the sacs for a permanent solution
Anal sac removal is not done routinely because the anal sac walls are quite fragile and the sacs themselves are located in muscle and near nerves innervating the anus thus making surgery quite delicate and time consuming and, if not done properly, potentially leading to post-operative complications such as permanently draining sinuses and faecal incontinence
I’m happy to teach anyone, who wants to learn, how to empty the anal sacs! BYO pet

* By Dr Libby Thompson