(1) one of a number of large sudoriferous glands in the mucous membrane of the anus; (2) an incorrect synonym for anal sac. (3) paired glands located at approximately the 4- and 8-o'clock positions when animal's anus is viewed from behind, present in dogs and cats. These small round saccular glands are located in the subcutis and produce an odoriferous oily discharge that likely serves to mark territory. They are connected to the terminal anus by a narrow bore tube; may become infected, impacted, abscessed, or neoplastic. Problems are more common in obese, constipated, or inactive animals.