CANINE ANAL SACS
The anal sacs (or so called scent glands) are inversions of the skin
where it joins the end of the digestive tract. The cavity formed
is, in most dogs, big enough to take a broad bean. There are two
sacs which lie on either side of the anus, producing a sickly smelling
fluid of varying consistency. Occassionally the opening of these
cavities becomes blocked and, unless expressed, the fluid may become
infected and a painful anal abscess will form and possibly burst to the
Anal sacs are often also called anal glands even though they
technically are not truly glandular in structure. Few topics raise dog
owners’ eyebrows (and lower dogs’ tails) faster than the subject of
anal sacs! These two small repositories of foul
smelling material technically are small pouches lined with cells
whose job it is to continually produce an oily semi-liquid substance
that is stored within the sac. It accumulates the heck are they
for?’ For a credible response I draw on my extensive knowledge of
A typical examination of a patient with anal sac disease (usually an
impaction or infection) hoes like this...
"You think it’s his what?” asked the incredulous owner of the
uncomfortable Basset Hound on the exam table. I restated my
diagnosis, knowing the owner probably never heard the term anal sacs
“Barkley has an anal sac infection. See how swollen and inflamed
it is next to his anus. In fact the abscess
is nearly ready to break through to the surface of the skin.
We’ll need to open this abscess and allow the infection to drain,
and then we’ll flush it, check the other anal sac, and send him home
on antibiotics. Warm compresses for a few days will speed up
the healing, too.”
WHAT ARE THEY
Anal sacs are small paired pockets located between the internal and
external anal sphincter muscles, one on each side of the anus at the 4
and 8 o’clock position. The sac empties through a short and
narrow duct to the surface near the inside edge of the anus. Each
sac is lined with abundant sebaceous (oil) glands and numerous
apocrine (sweat) glands. The secreted substance is a semi-oily,
brownish fluid that packs an odor strong enough to gag a maggot!
For unknown reasons some dogs' anal sacs produce a rather thick,
semi-solid material which is much more prone to impacting the sac due
to the sac's inability to pass this semi-solid material through the
narrow duct to
the outside. In many of these cases the sac will become infected,
cause pain and inflammation and even break through to the skin
surface. The abscessed anal sac may need surgery to provide
drainage and curettage of the damaged and infected sac and surrounding
tissue. Antibiotics are indicated in abscessed anal sac disease.
WHAT THEY DO
One study indicated that anal sac disorders affects
about 12% of dogs. There are a number of theories why dogs, cats,
skunks, and other mammals have anal sacs and what possible use they
may have. One theory states that anal sac contents, when excreted
with the passing stool or by anal sphincter muscle contraction, act
as a powerful territorial scent marker somewhat akin to humans posting
a No Trespassing sign. Another theory states that the anal sac
material lubricates hard stool, which makes passage easier.
Humans do not have anal sacs. It’s bad enough that some humans
get hemorrhoids, which are dilated, irritated blood vessels at the
anus; luckily, dogs do not get hemorrhoids.
CAUSES OF ANAL SAC PROBLEMS
There are no predictable antecedents to painful anal sac
disorders. Infections, obstruction and subsequent overfilling
(called impaction), and rupture with drainage through the perianal skin
are the most common clinical presentations. Anal sphincter muscle dysfunction, enlarged anal sacs that are not
compressed properly by the anal sphincter muscle, hypersecretion
from the anal sac lining, obstructed or constricted anal sac ducts
all may be predisposing circumstances for anal sac problems.
IMPACTED ANAL SACS
Some dogs may be born with very narrow channels that lead from the sacs
to the edge of the anus, thereby obstruction the flow of anal sac
material. Acquired damage to the duct can occur
when perianal infections, trauma, allergies and inflammation compress
or obstruct the narrow channel leading from the sac to the
surface. For unknown reasons some dogs produce a thick or dry
material from the sac lining which makes passage of the material
through the narrow ducts impossible.
There is no age or sex predisposition to anal sac pathology.
Uncommon in large breeds, infections and impactions are often
experienced by small breeds such as Toy and Miniature Poodles,
Chihuahuas, and Lhasa Apsos. Cocker Spaniels, Basset Hounds, and
Beagles rank high on the list of breeds affected by anal sac
Some groomers and animal health care workers believe feeding a diet
rich in fiber aids in emptying the sacs. The pressure of the firm stool
against the colon wall near the anus may help to express the anal sac
contents. Dogs that have an existing problem such as infection or
obstructed ducts, though, probably won’t respond to dietary changes;
modifying the diet with more or less fiber yields inconsistent
benefits. As a practitioner for over 35 years I have seldom seen
a change of diet have any beneficial impact on the frequency of anal
There is a difference of opinion regarding routine expressing of the
anal sacs. For example, veterinarian Mark Thompson
in his presentation about anal sacs in Current Veterinary Therapy
XIII, suggests routine manual expressing of the anal sacs should not
be done in a normal dog with no anal sac issues. Many groomers
make it a matter of routine, though, to express the anal sacs of their
dogs. Certified Master Groomer Sherri Glass, for example, has
grooming dogs for 14 years and has taught grooming for 5 years at
Dog Grooming Academy in Clyde, OH. She relates, “I teach students
to empty anal glands on all small dogs, about 20 pounds or less in
size. We also do any size dog at owners request. If dog
meet their dogs nutritional needs with high quality food, keep them at
proper weight, and provide plenty of good exercise, most dogs would not
have to have the anal sacs expressed.” Mr. Jeffrey
Director of the National Dog Groomers Association of America says “In
states were it is legal for groomers to express anal sacs, many
groomers express them externally only either as a part of the grooming
or at the owners request. When there is evidence that the sacs are
impacted, then they are not expressed and the owner is advised to bring
to the vet.”
HOW TO RECOGNIZE A PROBLEM
There is an 88 percent chance the thought of anal sacs will never even
occur to you. However, if your dog is one of the 12 percent that
scoots his rear bumper along the carpet, frequently turns to lick or
bite at the base of his tail or anal region, or displays discomfort
when passing stool, it would be advisable to make an appointment with
the veterinarian. If left untreated, anal sac impactions,
infections and abscesses can be a reoccurring nuisance for your dog
so be proactive about an evaluation if your dog displays any discomfort
in the tail or anal region.
THE ULTIMATE SOLUTION
“Do-it-yourself-anal-sac-expressing” can be done at
home once your veterinarian has instructed you. (Yuck… be
careful about contact with anal sac secretions or you’ll be very
unpopular with yourself and others!) Some cases respond to
infusion of the sacs with antibiotics in addition to oral
medication. In chronic cases, careful surgical removal of the
anal sacs can be curative; the dog never has another annoying bout of
anal sac disease. Be sure to discuss the pros and cons of surgery
if chronic problems lead you in
Copyright © 1998 Canine Inherited
Disorders Database. All rights reserved.
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Revised: October 30, 2001.
This database is funded jointly by the Sir James Dunn Animal Welfare
Centre at the Atlantic Veterinary College, University of Prince Edward
Island, and the Canadian Veterinary Medical Association.
Permission to reprint is granted by
Alice Crook, DVM Coordinator, Sir James Dunn Animal Welfare Centre
Atlantic Veterinary College University of Prince Edward Island
Anal Sacs (also Called Anal Glands or Scent Sacs),
Their Function and How to Properly Express Them
Q: My dog drags his
butt on our carpet, outside and everywhere. He seems to be very
uncomfortable. Is there anything I can buy that might give him relief ?
A: Many people own dogs for years without ever knowing
about anal sacs until it becomes quite obvious that their dog is having
a problem and requires a visit to the vet or groomer. Anal sac problems
are extremely common and can cause tremendous pain for your pet.
Anal sacs are two small glands just inside your dog's anus. They are
positioned at about five and seven o’clock in reference to the anus.
|click on image for larger view
Tiny ducts lead to the tissue just inside the rectum. They appear to be
used for territorial marking thus allowing dogs to identify one
another by means of the 'scent' left behind after defecating. As the
pet defecates, the anal sphincter squeezes the sacs against the hard
feces causing the anal secretion to discharge onto the fecal mass.
You have no doubt seen dogs new to one another, try and sniff
the other's rear end. An annoying habit to us humans, it is their
natural way of getting to know that dog and it's particular 'scent'.
Again, this serves as a sign post used to communicate with the other
dogs and cats. When walking about the area and again finding that
scent, many dogs will either urinate beside it (as a manner of
acceptance of that dog) or urinate directly on it (showing dominance or
rejection of the dog). Most dogs
are able to empty these glands voluntarily but certain breeds may need
a little help. It also seems that smaller dogs or obese dogs are
to this problem. In particular, small Poodles, Chihuahuas and
Pomeranians have a high incidence of anal gland problems. If your dog
is under 20 lbs., be sure to keep a close eye on this region.
A dog's lifestyle and diet (sedentary or confined for long periods
without the ability to defecate outside when needing to and little or
no fiber in the diet) may all contribute to the dog being unable to
empty their glands on their own.
If your pet has a history of scooting, you can rest assured the anal
sacs need attention. The emptying or 'expressing' of these sacs
is done in one of two ways:
EXTERNALLY: A rag or tissue is held up to the anus and
both sides of the anal area are squeezed. If the secretion is very
pasty, this method may be inadequate to empty the sacs.
INTERNALLY: A lubricated gloved finger is inserted in the anus
and the sac is squeezed between thumb & forefinger into a tissue
held externally. The procedure is repeated on the opposite side. If the
sacs have been emptied adequately, the scooting should resolve in a
couple of days.
You can learn to empty these sacs yourself (a disgusting task
akin to changing a really 'ripe' diaper). The secretion that comes from
these glands is brown in color and about the consistency of water or
oil. But remember, you are doing it for your dogs comfort, hygiene and
overall well being and your dog will be truly grateful for the relief
given. If left untreated, an abscess can form and rupture out through
the anus. This is why the anal sacs should always be checked by the
veterinarian or groomer whenever working with the pet. If the secretion
stays in the sacs for very long it begins to thicken and becomes like
peanut butter in consistency.
At this point it is very difficult to be expressed and subject to
bacterial invasion and abscessation. Once an abscess forms and there is
no route of escape for the secretion and pus, it may rupture through
the skin causing an unsightly mess and a good deal of pain for the pet
(See image below).
This is often mistaken for
rectal bleeding. If an anal sac abscess forms, it must be properly
treated by your veterinarian and a follow-up with antibiotics will be
|click on image for larger view
How Often Should Anal Sacs Be Emptied?
This varies from dog to dog. The best recommendation is to watch your
dog's behaviour, if he starts scooting again, it is time to have a look
at the sacs. If the scooting continues for more than a few days after
sac emptying, the sacs should be re-checked. For some dogs, the sacs
may be emptied several times in a row before they stay emptied. If you
are certain the sacs have been properly emptied yet your dog continues
scooting, another cause may be present such as itchy skin, tapeworms,
or even lower back pain.
What If My Pet's Sacs Seem to Require Emptying All the Time?
To avoid the expense of having the sacs emptied by your vet or groomer,
a non-invasive technique that helps some dogs is a change to a high
fiber diet. Give him fresh few baby carrots (two or three times a
week). This may harden his stools and help to express the anal glands
naturally and reduce the likelihood of impaction and subsequent
How Do You Treat This Disease?
Once your dog has had one occurring episode of anal gland disease, it
is more than likely it will develop more episodes. As an owner, you can
help prevent this problem by manually expressing the glands yourself
(or asking if your dog groomer provides this service), every couple of
months. You can also take your dog into your veterinarian's office and
have them do it.
Surgical Removal Of The Glands
If it seems that your dog is having reoccurring problems with
anal gland disease, you can have these glands surgically removed.
Because dogs no longer have a need for these glands, it doesn't hurt to
have them removed and it is the only way to permanently solve the
The Importance Of The Dog’s Anal Gland
By: Kirsten Hawkins
In the movie The Fisher King
there is a rather humorous scene in which Robin Williams’ character is
scooting himself along the ground by digging his heels in and dragging
his bare bottom across the grass. In a jubilant voice he calls out,
“Do you know why dogs do this? It feels GREAT!!”
Actually, that’s not the only reason. Dogs will exhibit this
behavior if the anus or hind quarters are itchy, but it can be a sign
of an impacted anal gland which can be a problem for some dogs.
The anal glands are located on either side of a dog’s anus and, in the
wild, serve as a method of marking the dog’s territory. When a dog
defecates the glands are naturally compressed and secrete a dark, foul
smelling liquid along with the bowel movement. When the sacs are
functioning normally they empty whenever the animal has a bowel
Sometimes, for various reasons, the dog’s anal sacs may become blocked.
When this happens a number of problems can develop. Some are benign as
a foul smell but the can lead to serious problems like diarrhea and
infection. To intervene before a blocked anal gland becomes an issue,
the glands must be expressed.
Expression of the anal glands is a simple medical procedure that can be
performed at home or by a veterinarian. Some people prefer to
let the vet take care of this task because they find it to be an
unattractive duty. To save the expense of a vet, however, it is
perfectly acceptable to express the anal glands yourself.
Expressing the Dog’s Anal Glands:
Expressing the anal glands is a simple matter. You’ll want to hold the
tail up and pull it gently toward the dog’s head. In the other hand
hold a tissue or paper towel and place your thumb on the left side of
the left gland and your forefinger on the right side of the right
gland. Squeeze firmly but not roughly and the glands should empty a
brown or yellowish liquid onto the tissue or towel. Impacted glands
will not empty as easily and may require an internal draining
technique. You can do the internal technique at home as well, but
you’ll need surgical gloves and a tube
of KY jelly.
Internal anal gland expression requires that the sacs on either side of
the anus be expressed individually and will require that you place your
thumb on one side of the gland and your forefinger inside the dog’s
rectum in order to squeeze and express the gland. Impacted glands will
be harder to drain and the fluid may be thick and pasty with a foul
odor and a dark brown, grey, or black color.
Infected anal glands may produce a discharge of bloody pus and can be
an indication of a more serious problem. The infection should
be fought with antibiotics so a vet should be contacted immediately if
the dog seems to have such an infection.
Kirsten Hawkins is a
dog lover and animal expert from Nashville, TN. Visit http://www.doghealth411.com/
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my own experience I have found that if a pet has trouble clearing the
anal glands whilst defacating a handfull of bran in
the food certainly aids the process. It works by enlarging the
faeces so that it clears the glands on exiting the anus.
Watch This Video on
to Express Your Dogs Anal Glands
The above information is simply
informational. It's intent is not to replace the advice of a
veterinarian nor to assist you in making a diagnosis of your pet.
Please consult with your own veterinarian for confirmation of any
diagnosis. Your pets life may depend on it.