Anal Glands on Dogs: What You Need to Know

By Barri J. Morrison, DVM on Mar. 31, 2022

There are times, though, when these glands become full, impacted, or infected. Impacted or diseased anal glands can be painful, so it’s important to recognize the signs of an issue and know what to do when it happens. When signs of anal gland disease persist, you should contact your veterinarian to schedule an exam for your dog.

Here’s what you should know about anal glands in dogs, from how they work and how they’re expressed to the signs of anal sac disease and when to go to the vet.

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What Are Dog Anal Glands?

Anal glands, or anal sacs, are two small pockets, each about the size of a small grape, located on the right and left side of a dog’s anus. Each gland connects to a small tube that secretes a very distinctive, foul-smelling fluid.

Under normal circumstances, when stool passes through the anus, it applies pressure to the glands and releases (expresses) the fluid.

Both male and female dogs, as well as cats and other animals, have anal glands. These glands are not essential to your dog’s health, and they can live without them if they need to be surgically removed for medical reasons.

Do Dogs Need to Have Their Anal Glands Expressed?

Most dogs involuntarily express their anal glands. If a dog’s nutritional needs are being met with high-quality food, and they maintain a healthy weight and get plenty of exercise, they should not need to have their anal glands expressed. If your dog is not having an issue, there is nothing you need to do.

Check with your vet if you are wanting to do routine expression. Your vet may recommend leaving the anal glands alone if they are not causing a problem, or they may agree to routinely express them to avoid a medical issue.

Some dogs, however, require their glands to be manually expressed. If the consistency of your dog’s stool changes, their anal glands will not be naturally expressed. Then the liquid in the glands will thicken, making it harder to be able to express. If this happens, the glands can become irritated, inflamed, infected, and even impacted.

Once your dog starts to have issues with anal gland infections, impaction, or abscessation, it is usually best to have their glands expressed every 3-4 weeks to prevent the issue from happening again. Your dog’s anal glands can be expressed by your veterinarian, a veterinary technician, or even some dog groomers.

How to Express Your Dog’s Anal Glands

If your vet has agreed that your dog requires their anal glands to be expressed routinely, they might instruct you to do so at home if you are comfortable. Make sure that you are confident that your dog will not react aggressively.

If you see blood or pus around your dog’s anus, or if your dog seems very uncomfortable, do not attempt to express their anal glands at home. Instead, make an appointment with your veterinarian right away.

To express your dog’s anal glands at home, you need:

Latex gloves
Petroleum or a water-based lubricant
Another person to help restrain your dog

Follow these steps to express your dog’s anal glands:

If your dog is small, place them on a table or counter in front of you. If you have a large dog, you can kneel behind them.
Have another person hold your dog by placing one arm underneath and around their neck, and the other arm around the rest of your dog’s body, hugging them close.
Put on a pair of latex or similar gloves and lubricate your index finger with petroleum jelly or a water-based lubricant.
Lift up your dog’s tail and gently insert your index finger into the rectum approximately 1 inch.
Feel with your index finger and thumb for a firm pea- or marble-sized object at the 5 or 7 o’clock positions.
When you have found one gland, place a paper towel between the dog’s anus and your hand and gently milk the gland’s contents outward by applying pressure on the farthest side of the gland and squeezing toward you. Do not use more pressure than you would feel comfortable applying if you were pressing on your eyes, for example.
You should barely be able to feel the gland when it’s empty.
Wipe the anal area clean.
Repeat on the other side for the other gland.

Are Certain Dogs Prone to Anal Gland Problems?

Anal gland problems are predominantly a small dog breed issue, but they can affect larger breed dogs as well. Toy and Miniature Poodles, Chihuahuas, Lhasa Apsos, Cocker Spaniels, Basset Hounds, and Beagles rank high on the list of breeds affected by anal gland conditions.

Other factors that may increase the chances of anal gland issues include:

Chronic skin conditions (seborrhea, skin infections, or itchy skin)
Obesity
Inadequate dietary fiber 
Change in stool consistency: soft stool, diarrhea, or constipation
Parasites (both internal and external)
Food and/or environmental allergies
Genetics (more common in small breeds)

Signs of Issues With Your Dog’s Anal Glands

The most common signs your dog may be having trouble with their anal glands include:

Scooting
Frequently turning to lick or bite their hind end
Straining to poop
Showing discomfort when pooping (dyschezia)
Not wanting to sit
Anal discharge

Dogs might also have the following signs:

Crying or whimpering
Becoming withdrawn or lethargic
Not wanting to eat or drink
Swelling or redness in the anal area

If these symptoms persist or affect your dog’s behavior, they should be examined by their veterinarian as soon as possible. If left untreated, anal gland impactions, infections, and abscesses can become major problems.

Types of Anal Gland Problems in Dogs

“Anal sac disease” is a broad term that includes a few specific conditions, like anal sac impaction, anal sac abscess, anal sacculitis, or apocrine anal gland adenocarcinoma, a type of anal gland cancer.

Anal Gland Impaction

Impacted anal glands will cause moderate pain in dogs. When the anal gland fluid thickens, this pasty, brown material clogs the glands and creates hard masses. In average cases of impaction, the anal glands can be expressed with significant pressure.

Anal Gland Infection or Abscess

A dog suffering from an anal gland infection or abscess will be in moderate to severe pain. If the gland is infected, the bacteria from the infection causes pus to build up inside the gland. An infection can then lead to an abscess when the pus-filled sac and swollen tissue cause the gland opening to be obstructed.

You may see discoloration around the anal area or a red, hot, swollen spot on the hind end, often next to or inside the anal opening.

Ruptured Anal Gland Abscess

If an abscess is left untreated, it can rupture, and your dog will be in severe to extreme pain. The ruptures (fistulas) lead from the anal gland through the skin. You may see a greenish yellow or bloody pus coming from the ruptured gland.

Anal Gland Cancer

The anal glands may also be the site of cancerous tumors. The most common type of anal gland cancer is known as apocrine anal gland adenocarcinoma. This condition may not cause your dog any pain. It’s more common in older, female dogs. Certain breeds such as German Shepherds and Dachshunds are at higher risk.

Symptoms associated with anal gland cancer include bloody stool, bleeding around the anus, swollen back legs, vomiting, increased thirst, increase urination, and lethargy. Your vet may also find elevated calcium levels in the blood (e.g., hypercalcemia). The anal glands may also be enlarged because of the mass, but no material is able to be expressed from the gland.

Treating Anal Gland Issues in Dogs

These conditions should be diagnosed by your veterinarian after a complete physical examination, including a digital rectal exam. Additional testing such as an ultrasound, fine needle aspirate, tissue biopsy, and/or a bacterial culture and sensitivity might be performed to help make a specific treatment plan for your dog.

Most cases of anal sac disease can be treated with manual expression of the glands and local treatment with antibiotics and/or steroid ointments. Some cases will require oral antibiotics and anti-inflammatory pain medication. In severe cases, surgical intervention might be needed.

For anal gland cancer, your vet will need to determine if it has spread to the lymph nodes or other areas. You will need to consult a veterinary oncologist, and the treatment might include removal of the anal gland and sac, chemotherapy, or radiation.

Tips for Keeping Your Dog's Anal Glands Healthy

Eating a diet with adequate fiber can help keep your dog’s anal glands healthy. Fiber promotes healthy digestion and proper stool formation. The force of the firm, bulky stool against the colon wall near the anus can help express the anal glands during bowel movements.

Keeping your dog at a healthy weight can also contribute to healthy anal glands. Overweight dogs tend to accumulate excess fluid in their anal glands because their body fat reduces the pressure on the sacs during pooping. If your dog is overweight, speak with your veterinarian about a weight-loss plan. A combination of diet and exercise will help your dog reach and maintain a healthy weight.

Here are several dog food formulas that are high in dietary fiber:

Discuss the options with your veterinarian before you make any diet changes for your dog.

You can also add dietary fiber to your dog’s diet and reduce the risk of anal sac disease with dietary supplements. Omega-3 fatty acids and fish oil supplements have natural anti-inflammatory properties and may help reduce irritation around an affected anal gland. Probiotics formulated with fiber also help promote intestinal health.

Recommended supplements include: