Anal Sacs

Anal sacs, sometimes called anal glands, are normal structures for every dog and cat. They consist of two small sacs located at the 4:00 and 8:00 position around the anus. The lining secretes a musk-like substance that has a very potent odor. The animal with the best-known anal sacs is the skunk, which can actually expel their anal sacs in a spray to ward off potential danger. Their function is primarily to identify an individual animal. Wild animals use the secretions from these glands to “mark” their territory. At the end of each defecation, an animal will contract the anal muscles several times, emptying a small amount of the anal sac contents on top of their dung pile. When animals meet, they will sniff under each other’s tail. (AKA the opening scene in Dr. Doolittle 1). They smell the odor of the substance in the anal sac. Each animal’s odor is unique to that animal and animals can identify each other by that odor.
Problems develop when the anal sac in unable to empty and they fill up, causing pressure and discomfort. Two causes that lead to full anal sacs include: 1) Insufficient pressure to empty the sac due to obesity or older age; and 2) Blockage of the sac opening, usually by fecal material. Typical signs of full anal sacs include “scooting” along the ground, licking excessively at the anal area, and/or an occasional “leaking” of the gland causing a foul odor when the pet is around. A more serious condition occurs when the sac becomes infected. When this happens, the cat or dog will run a fever and have a great degree of swelling and pain.
Treatment of blocked anal sacs consists of applying pressure to the sac manually, emptying out the contents. On occasion, the sacs have been blocked so long; their contents have begun to dry to a paste consistency. When this happens, we will insert a small catheter through the anal sac opening and flush the sac with saline until it is empty. An antibiotic ointment is then infused into the sac. For sacs that are infected, the same flushing and infusing is done, and the pet is placed on antibiotics. Some pets continually have anal sac blockages and it may be recommended to have the sacs removed to avoid future problems.