Anal Glands

The anal sacs are located on both sides of the anus between the internal and external anal sphincter muscles. They are present only in carnivores. They are oval in shape and about 1 cm in diameter in a medium-sized dog. A short duct opens on both sides on the ventrolateral aspect of the anus. The sacs provide storage for the secretion of the coiled glands located in the wall of the sacs. The strong-smelling sebaceous secretion acts as a territory marker. Impaction of the sacs is a frequent problem requiring manual emptying.

Circumanal glands are present in a subcutaneous zone around the anus. These are also sebaceous glands but do not possess a reservoir.