By Carrie Hyde, The Spaw Pet Life Coach | February 8, 2022

Talking about dog anal glands may not be something you want to do. But if you’ve ever dealt with anal gland woes, then you know that this uncomfortable subject can quickly become much more uncomfortable for your dog. Not to mention, quite stinky!

For the health and wellbeing of your four-legged friend, it is crucial that you understand what anal glands are, why they exist, and how different diets can affect how well they function. In this article, we’ll also discuss two very important topics: should anal glands be expressed manually and how to improve anal gland health to avoid stinky, uncomfortable, and even dangerous situations.

What Are Anal Glands?

Anal glands aren’t actually individual glands at all, but rather fluid-filled sacs that contain many small sebaceous and apocrine glands. These sacs exist in most mammal species, including humans, though the size and function differ between species.

In dogs, the anal sacs are located on each side of the anus just below the midline. Each sac is filled with an oily brown substance that has a very distinct metallic, fishy odor. This substance is made up largely of fatty acids, diamines, and scent markers.

The glands inside the sacs continuously produce this oily, waxy liquid. As feces pass, they apply pressure to the sacs and force the liquid out through ducts that connect just inside the anus. Without regular, firm stools, it is possible for the anal sacs to accumulate too much fluid, which can cause inflammation, infection, and rupture.

Anal glands can also be emptied during times of great stress, such as during a fight. It is unclear if this is an intentional act meant to distract the potential threat or an involuntary occurrence.

What Are Anal Glands For?

The purpose of anal glands is still somewhat of a mystery, though there are many theories that hold weight.

Studies into the anal secretions of wolves have shown that the chemical components of this stinky liquid change based on the individual’s sex and the time of year. This lends weight to the theory that anal glands are used as a scent marking and communication tool.

Just as canines use urine to mark their territory, they also appear to use their feces, thanks to the addition of this oily liquid to their poop.

Due to the high lipid profile of anal gland secretions, it is also theorized that this fluid helps lubricate feces. Since larger feces put more pressure on these glands and therefore release more liquid, it makes sense that the glands could act to protect anal tissue against tears.

One common theory that has not been well backed by research is that the anal glands help detoxify the body. Neither sebaceous nor apocrine glands, which are common throughout the skin of all mammals, play a role in moving toxins out of the body.

Furthermore, the chemical makeup of anal gland secretions does not appear to contain any heavy metals or other common toxins. However, there is some evidence that both a high toxicity load in the body and antibiotic use can affect the composition of anal gland fluid. This is likely the effect of changes to the beneficial bacteria that exist in the glands due to die out caused by these conditions.

How Diet Affects Anal Gland Health

While the exact purpose of anal glands is somewhat of a mystery, one thing we do understand very well is how diet affects the health and function of these sacs.

Without firm, bulky stools passing through the anus, the fluid in the anal glands cannot be released. If too much fluid builds up, the sacs will begin to swell, causing the duct to close and preventing future bowel movements from emptying the sac. This can lead to the formation of an abscess and the rupturing of the sac.

Certain diets, such as those high in starch or lacking the right type of fiber, are known to cause loose stools that contribute to anal gland problems.

High Starch Diets Lead to Gut Inflammation

As we’ve discussed before, dogs evolved to eat a diet very high in animal meat and fat. Only about 1% of a wolf’s diet–domestic dogs’ closest ancestor–is made up of plant material. And most of this 1% is composed of fiber, not starch.

While dogs have adapted to less carnivorous diets, they still lack the enzymes necessary to break down starch. Amylase, the most important enzyme for digesting starch, is only produced in small quantities by the canine pancreas, with some breeds producing less than others. Without this necessary enzyme, high-starch commercial diets cause excess inflammation in the gut.

This can lead to reduced water retention in the large intestine and frequent, loose stools.

High-starch diets will also change the balance of flora in the gut. The healthy canine gut contains a wide range of bacteria that specialize in breaking down different kinds of meat, bone, and tissue. When more starch is fed than protein and fat, these bacteria die off and starch-eating bacteria take over.

This lack of variation in the gut biome can lead to yeast overgrowth, more inflammation, and nutrient absorption issues. All of these factors together combine to create runny stools that fail to express the anal glands.

Bone Roughage vs Plant Fiber

One common misconception is that adding plant fiber to a dog’s diet can help improve anal gland health. While it is true that more fiber can bulk up stools in humans, the story isn’t as straightforward in canines.

Because dogs evolved to eat a high-meat diet, their digestive systems and gut biomes are optimized to use animal matter to create bulky, healthy stools. Most important to this process is bone roughage.

Bone roughage consists of the hard calcium phosphate framework that makes up bone. While some of these minerals will be absorbed into the body, most will pass through the gut and help build up stool without pulling too much water from the large intestine.

This is similar to what soluble plant fiber does in omnivores and herbivores. This gelatinous form of fiber helps add bulk to stool. Insoluble fiber, which stimulates the release of water from the large intestine and has a slight laxative effect, comes together with soluble fiber to create healthy bowel movements in humans.

Insoluble fiber has an even more pronounced effect on the canine gut and can quickly lead to loose, watery stools. Soluble fiber can help add bulk, which is helpful for emptying anal glands, but the effect is not as beneficial as the effects from bone roughage.

If your dog needs help bulking up their stool, ground bone is the first supplement you should turn to. If that is not an option, soluble fiber, such as psyllium or pumpkin puree, may be helpful.

Do Anal Glands Need to be Manually Expressed?

There are many people who say that expressing your dog’s anal glands is a helpful way to keep them functioning properly. Others caution against ever manually expressing them. The truth is a little less black and white.

Frequently manually expressing your dog’s anal glands has the potential to cause injury to the sacs or the ducts, causing scar tissue to form that could impede how well they function in the future. There is also some truth to the idea that manually expressing too often could create a sort of dependence in which the glands only ever fully empty when manually stimulated.

But most important to the argument against manual expression is the fact that if your dog’s anal glands need this done, there is a larger problem that needs to be addressed.

Rather than relying on your groomer to manually express the glands every month or so, you should be working to improve your dog’s diet and gut health to help them build stool capable of emptying the glands naturally.

Of course, if your dog’s glands are already impacted, natural expression is unlikely to occur. In the case of impaction, manually expressing the glands is necessary to avoid further damage. But, again, you should still work to improve your dog’s digestive health to prevent a need for future manual expression.

How to Tell If Your Dog’s Anal Glands Are Impacted

Signs that your dog’s anal glands are full or becoming impacted include:

• Scooting their bum on the ground
• Walking and turning quickly to look at their hind end
• Licking or chewing on their bum
• Redness or swelling around the anus
• A foul metallic or fishy smell coming from their hindquarters

If your dog’s bum is red, swollen, and painful, it’s possible one of the glands has already abscessed or even burst. This condition is more serious than an impacted anal gland and requires veterinary intervention.

If caught in the early stages of impaction, you may be able to facilitate natural expression by adding bone roughage or soluble fiber to your dog’s meals for a few days. If the glands are very swollen and bothersome but not painful, manual expression is likely necessary to relieve the pressure before the situation progresses.

If your dog is chewing or bugging their bum, use a cone to keep them from getting to the area. You can also apply some coconut oil to the area to help relieve the swelling and irritation.

Some dogs will continue to bug their bum after manual expression. This is normal and expected. If this happens, use the cone and coconut oil method outlined above to help them find relief sooner.

How to Improve Anal Gland Health

If your dog experiences frequent anal gland problems, there are some steps you should take to help them find lasting relief.

Provide a Biologically Appropriate Diet

The sad truth is that very few commercial diets have enough protein, fat, and bone roughage to help your dog maintain healthy bowel movements. Dry kibble, especially, is known to irritate the gut due to its dehydrating nature, high starch content, and high insoluble fiber content.

If your dog struggles with loose stools, constipation, or anal gland problems, consider switching them to a homemade fresh, raw, or cooked diet under the guidance of a certified canine dietician. If this isn’t possible, then choosing a commercial raw or dehydrated diet is a good secondary option.

Address Causes of Digestive Upset

A low-quality diet isn’t the only thing that can cause gut inflammation. Stress, parasites, and allergens can also irritate the gut and lead to loose stools and anal gland problems.

Along with changing their diet, you should take steps to minimize your dog’s stress by assuring they get plenty of activity and stimulation. If parasites are a possibility, an appointment with the vet is in order. Just be sure to double your efforts to restore gut health once the parasites have been eradicated as the medicine used to treat these infections can be as damaging as the bugs themselves.

If your dog has additional symptoms, such as a lackluster coat, excessive shedding, or skin infections, a food allergy might be the cause of all their problems. Consider doing an elimination diet to identify the allergen, then work to remove it from their diet.

Supplements

For most dogs, providing a biologically appropriate, allergen-free diet is enough to get their anal gland health back on track. But a number of factors can cause symptoms to persist long after a diet change has been made. These include problems with scar tissue in the ducts, genetic predisposition to thicker anal gland fluid, and natural size and shape of the sacs.

Whether your dog is genetically predisposed to having anal gland issues or just still recovering from past trauma, there are supplements that can help.

• Slippery Elm – This herbal supplement helps enhance the mucus layer on the inner membrane of the intestines. This helps the gut heal faster, helps stool move more smoothly through the gut, and helps prevent diarrhea and constipation.
• Digestive Enzymes – Adding digestive enzymes to your dog’s food can be especially helpful if they have pancreatic issues or if you are still transitioning from kibble. These aid in digestion and help form firmer, bulkier stools.
• Probiotics – Anal gland issues are a clear sign of digestive problems. Whether those problems were caused by a gut biome imbalance or something else, you can be sure their microbiome has suffered. Adding probiotics to their food via a quality supplement or naturally fermented product, like goat’s milk or apple cider vinegar, can help restore that balance.

Feed Whole Small Fish

Two things that are known to improve gut health in dogs are bone roughage and omega fatty acids. Both of these things can be found in high quantities in whole small fish such as sardines.

By adding these to your dog’s meals you can provide them with a high-quality, unprocessed source of these vital nutrients without breaking the bank on supplements that deliver less than they promise.

Healthy Dog, Healthy Glands

Like your dog’s skin and coat, the anal glands are yet another indicator of whole-body health. If they are continually struggling with impacted glands you can be sure there is something bigger at play. By improving their diet, eliminating causes of gut inflammation, and supplementing for maximum anal gland health, you can put an end to scooting and bum chewing while improving your pet’s overall wellbeing.

By Carrie Hyde, The Spaw Pet Life Coach | February 8, 2022

Written for The Spaw by Sara Seitz, Professional Freelance Writer and Novelist with Pen and Post Carrie Hyde is the founder, owner, and Pet Life Coach of The Spaw in Tustin, CA. Carrie’s extensive experience and understanding of pet nutrition and coaching enabled her to create The Spawdcast, a podcast dedicated to educating pet parents and pet industry professionals on ALL the options available to their pet. Her mission is to open pet-owner’s eyes to the questions they may not even know to ask, to shine light on the many myths that have been part of pet care for decades and to offer whole solutions for their pets. Carrie Hyde is a certified pet nutritionists with the goal of helping pet parents & pet professionals with a new understanding about how to care for pets in a “whole and natural” way.