Dog Owner's Home Veterinary Handbook.pdf - Mr. Walnuts

290 •DOG OWNER’S HOME VETERINARY HANDBOOK
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.
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 rear area.
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 Constipation, page 280).
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