Anal sac disease is a very common problem in dogs and can also affect cats. The anal sacs, also called anal “glands”, are located on either side of the anus at approximately 4 o’clock and 8 o’clock. Each anal sac is connected to the anus by a small duct. The anal sacs are lined with specialized sebaceous glands that produce a dark foul-smelling liquid. This fluid was originally present to mark the animal’s territory and scare away predators. Each animal’s scent is completely unique. A small amount of the fluid should be expressed with every bowel movement. They can also express due to forceful sphincter muscle contractions that can occur when an animal is very frightened.
Symptoms of anal sac disease can include but are not limited to the scooting or dragging the anus, excessively licking the anal area, pain near the anus, redness or swelling around the anus, and bloody or sticky discharge.
Anal sac disease is a relatively common problem in all breeds/sizes of dog. Anal sac disease can refer to anal sac impaction, infection, or abscess. Any of these conditions can happen to one or both anal sacs. It is relatively common for these problems to recur or escalate once they occur. Anal sac impaction occurs when anal gland material does not drain correctly and builds up in the anal sacs. The fluid can also become thickened or solidified which causes swelling of the anal sacs and pain/discomfort. Anal sac infection occurs when bacteria begins to grow in the anal sac fluid producing pus or blood. Anal sac abscess occurs when this infection becomes trapped in the duct. This often happens when the anal sac material becomes thickened and blocks the anal sac duct. The pressure in the anal sac can continue to build until it eventually ruptures through the skin next to the anus, sometimes causing damage to the surrounding muscle.
Treatment for anal sac disease varies depending upon the severity of the disease. Anal sac impaction is very common and is usually treated by manually emptying (expressing) the anal sacs. This needs to be done every 3-4 weeks in some dogs and can be done by a veterinary technician. For dogs with a chronic problem owners may choose to learn to do this at home. Anal sac infection usually required expression of the anal sacs in addition to oral antibiotics and possible pain medication given 1-2 times daily for 10-14 days or longer. Anal sac abscesses must be opened and drained if they have not already ruptured through the skin. This can involve the use of IV sedation if the area is too painful to manipulate while the dog is awake. In addition to oral antibiotics and pain medication a topical antibiotic and warm compresses should be applied twice daily until the area has healed. Recurring anal sac disease can also be treated through multiple courses of antibiotics, sedation in order to flush the anal sacs and then infuse them with a specialty antibacterial gel called Clinzgard, which thickens and remains in the anal sac for 7-10 days. In rare cases where none of these treatments are effective, surgery is considered in order to remove the anal sacs. General anesthesia is required for the surgery and the primary complication that may occur is fecal incontinence due to nerve damage.
Anal sac disease can result for a variety of reasons. It is often linked to food allergies. Many dogs will develop an allergy to a protein or wheat in their food. Switching to a novel protein or hypoallergenic diet can often alleviate anal sac disease. Iams Fish and Potato, Hills Z/d, and Royal Canin HP are all recommended diets sold here at River Road Veterinary Clinic. Anal sac disease can also arise in dogs that have chronically soft stools. The addition of extra fiber (such as canned pumpkin) to the diet can make the stools more bulky, allowing for the regular expression of the anal glands with each bowel movement. In a majority of dogs the cause of anal sac disease is unknown.
There is no way to completely prevent anal sac disease from recurring. Bringing the dog in for manual expression of the anal sacs on a regular basis, adding fiber to the diet, and trying a novel protein or hypoallergenic diet are all things an owner can do to reduce the likelihood of recurring disease. Paying close attention to your dog and calling the veterinarian as soon as he/she begins to scoot, lick, or act uncomfortable is also very important. Addressing anal sac disease as early as possible gives your dog the best chance for an uncomplicated recovery.