The dog has two anal sacs or glands
located at five and seven o’clock in reference to the circumference of the
anus. They can be seen by drawing down on the skin of the lower part of the
anus and looking in those locations.
The anal sacs are similar to scent glands. In skunks they serve a defensive
purpose. In dogs they produce an odor that identifies the individual and marks
his stool to establish territory. This is why dogs greet each other by sniffing
at the rear.
Some adolescent or adult dogs (over six months of age) urinate or defecate inside the house. House soiling can occur in any location of a home, but sometimes pet parents will notice that their dog soils more in certain locations. The location can indicate the cause. For instance, soiling might occur only in infrequently used rooms or on a specific kind of surface, or only on furniture and areas that smell strongly of a person or other animal, such as beds and sofas. Soiling might also occur only...
The anal sacs are emptied by the pressure of stool passing through the anus.
They can also be emptied by forceful contractions of the anal
sphincter-something that may happen when a dog is frightened or upset.
Anal sac disease is a cycle
that begins with impaction and progresses through infection to abscess and
rupture. Dogs with anal problems may develop tonsillitis from licking at the
Anal Sac Impaction
Impaction is the accumulation of pasty secretions in the anal sacs. The sacs
become distended and mildly tender. The expressed secretions are thick and dark
brown or grayish brown. The sacs become impacted when they don’t empty
completely. This may be due to insufficient pressure on the sacs during
defecation because of small, soft stools; inadequate sphincter pressure; or
blockage of the openings by thick, dry secretions. Impactions tend to occur
most often in small-breed dogs and in overweight dogs.
Treatment: Impaction is treated by manually expressing the secretions. Dogs
with recurrent anal sac impactions should have their sacs emptied at regular
intervals. Place the dog on a high-fiber diet or a bulk laxative to increase
the size of the stools (see
How to Empty the Anal Sacs
Manually emptying the anal sacs is called expressing them. It is not
necessary to express the anal sacs unless the dog has an anal sac disease, or
when frequent malodor poses a problem. Begin by putting on a disposable latex
or plastic surgical glove. Raise the dog’s tail and locate the openings as
shown in the figure on this page. If they’re full, the anal sacs can be felt as
small, firm lumps in the perianal area at the five and seven o’clock