ANAL GLANDS
The anal glands, or sacs, are located on either side of the anus, under the skin and sphincter muscle. They connect to the anus by means of small canals, or ducts (see diagram). Anal sacs produce and store a dark, foul-smelling fluid. Anal glands are the same type of gland that a skunk has, but serve no useful purpose in the dog or cat.
Normal emptying of the sacs is caused by the pressure of a bowel movement, and the contractions of the anal sphincter muscle.
Diseases of the anal glands include:
1. Impaction -- normal secretions are thick, and cannot escape
2. Infection -- bacteria trapped within the gland produce a yellow or bloody pus. Other parts of the body may also be infected.
3. Abscessation -- as a result of infection, a hot, tender, red swelling forms near the anus. It may burst and drain bloody pus.
Symptoms of anal sac disease are:
Scooting or dragging the anal area
Excessive licking under the tail
Soreness near the tail or anus
Swollen area near anus
Bloody or sticky drainage under the tail
Treatment may include:
- Massage to empty the sacs
- Application of warm, moist heat (hot packing)
- Antibiotic medication
- Instilling medication into the sac
- Surgical drainage (lancing)
- Surgical removal of the sacs

Your doctor will help you decide which treatment is best for your pet. Remember that obesity and poor diet are predisposing factors in anal sac disease.