Anal gland expression

What the anal sacs are

The anal sacs sit at roughly 4 and 8 o'clock relative to the anus, each connected to the anal opening by a short duct. They produce a foul-smelling fluid used in scent-marking and territorial communication. In a healthy animal, firm stool compresses the sacs during defecation, expressing a small amount of fluid naturally.

When manual expression is needed, and when it isn't

Routine expression on a healthy animal with no symptoms is unnecessary and may be counterproductive, repeated manual emptying can train the sacs to lose their natural emptying tone. Expression is indicated when the animal shows clear signs of full or impacted sacs: scooting, licking at the perianal area, painful defecation, or a foul odor.

Chronic recurrent impaction is usually a downstream problem. Common drivers include soft stool (diet-related or GI inflammation), obesity, allergic skin disease causing ductal inflammation, and breed conformation. Treating the upstream cause beats more frequent expression.

External vs internal expression

• External, squeezing the sacs through the skin. Common in grooming settings; safe but incomplete, and inappropriate for impacted or infected sacs.
• Internal (digital), gloved finger inserted into the rectum, gland palpated and emptied bilaterally. The veterinary standard; required for impactions, abscesses, or diagnostic evaluation.

Why it matters

'My groomer expresses them every visit' is one of the most common reasons a dog ends up with chronic anal sac problems. The sacs are not designed to be manually emptied on a schedule; doing so masks the real driver, usually diet, allergy, or weight, that the owner should be addressing instead.