What's Causing That Strange Odor from Your Dog?
There's a lot of misinformation out there about managing a dog's anal glands among groomers and even some veterinarians. Should your dog's anal glands be expressed regularly or could the practice actually be harmful? Are your dog's anal gland issues due to something you are (or aren't) doing?
Reviewed by Dr. Becker
Join the Bark & Whiskers™ Family
Sign up today for our FREE newsletter, packed with expert advice and insider tips to keep your beloved pet in tip-top shape.
View our Privacy Policy and Terms of Service.
STORY AT-A-GLANCE
- Your dog has two anal glands, oval-shaped sacks that sit just inside the rectum on either side of the anus at about the 8:00 and 4:00 positions
- When your dog poops, if the stool is of normal consistency, a smelly, oily fluid is expelled from the anal glands through tiny ducts and onto the feces
- The three most common causes of anal gland problems in dogs include dietary issues — resulting in loose stools — trauma to the glands, and malposition of the glands
- One of the most common signs that your dog's anal glands aren't expressing properly is scooting their rear end across the floor
- A combination of dietary adjustments and natural GI anti-inflammatories is usually helpful to restore anal gland health
Editor's Note: This article is a reprint. It was originally published August 23, 2023.
Have you ever noticed a fishy-smelling foul odor coming from your dog's backside? While it may be unpleasant to you, this pungent odor serves an important purpose to your pup. It comes from a small amount of oily fluid expressed from your dog's anal glands, and it's used to mark territory, allowing dogs to leave personal biochemical information for other dogs to investigate.
In fact, that strong odor is unique to your dog, with each canine producing a slightly different scent.1 While you probably don't give much thought to your dog's anal glands, if there's a problem, you'll probably know it, as the smell is difficult to miss.
All About Your Dog's Anal Glands
Your dog has two anal glands, oval-shaped sacks that sit just inside the rectum on either side of the anus at about the 8:00 and 4:00 positions. If your dog is fearful or stressed, fluid may involuntarily be expressed from the anal glands.2
However, when your dog poops, if the stool is of normal consistency, the oily fluid is expelled from the anal glands through tiny ducts and onto the feces. Anal glands empty from the pressure of the stool as it passes through the rectum and anus. This is a useful design of nature, but unfortunately, many dogs often have loose stools or irregular bowel movements that don't provide sufficient pressure against the anal glands during evacuation.
One of the most common signs that your dog's anal glands aren't expressing properly is scooting their rear end across the floor. Licking or itching the anal area, difficulty pooping or pus and blood near the rectum or in the stool are other signs of anal gland problems in dogs.3
Top Three Causes of Anal Gland Problems in Dogs
If your dog's anal glands aren't regularly expressed, the oily substance builds up in the glands, thickens and isn't expressed, resulting in enlargement, impaction and irritation of the glands. Anal gland infections are usually bacterial in nature and cause irritation and inflammation. As the infection progresses, pus accumulates within the anal gland.
Left untreated anal gland infections can progress into an abscess that will grow until it ruptures. If this occurs, infusing the anal glands with ozonated olive oil or silver sulfadiazine (diluted with colloidal silver) can be helpful. Anal gland tumors can also cause anal gland swelling. These are usually malignant and may cause elevations in blood calcium levels, which is something your vet will check for if a mass is palpated.
If your dog is obese, the insufficient muscle tone and extra fatty tissue may contribute to anal gland problems. Certain perianal skin disorders, systemic hormonal imbalances and infections may also increase risk. However, the three most common causes of anal gland problems in dogs include:
- Dietary issues, resulting in loose stools
- Trauma to the glands
- Position/location of the glands
Eliminate Inflammatory Foods from Your Dog's Diet
Recurrent anal gland issues secondary to intermittent gastrointestinal problems often means there's a problem with an ingredient or the type of food she's eating. The last part of your dog's digestive tract is her rectum, anus and anal glands, so irritation related to food is commonly expressed in these areas. Eliminate inflammatory foods from her diet, including corn, potatoes, legumes, oatmeal, wheat, rice, soy. Discontinuing foods containing high amounts of pro-inflammatory omega-6 fatty acids, including chicken and all vegetable oils, can also help.
If you don't have a clue what's setting your pup's digestive system off balance, you can order a NutriScan test to identify food sensitivities, followed by a novel diet depending on the results of the scan. When a dog is having a reaction to something in her diet, her body needs a break from that food. After determining her food intolerance(s), my recommendation is to introduce a novel diet to promote gut healing. This means transitioning her to a different food she isn't sensitive to made up of ingredients her body isn't familiar with.
A balanced, homemade fresh food diet is a perfect way to do this, as many commercial foods contain ingredients you're probably trying to avoid. This is true even if they're labeled as containing "novel proteins." However, if homemade isn't an option, look for a human-grade commercially available fresh food containing an uncommon protein, produced by a company you trust.
The great thing about feeding a nutritionally optimal, species-specific diet is that it will address both food sensitivities and intermittent poor stool consistency. Diarrhea can quickly contribute to anal gland issues, since there's no pressure from firm feces to help expel their contents.
Adding prebiotic fiber such as 100% pure pumpkin puree, marshmallow root or slippery elm powder to her diet can be helpful, but if your dog is experiencing diarrhea regularly, see your integrative veterinarian to get to the bottom of what's causing it. Often, diet is the culprit but there can also be a microbiome imbalance, digestive enzyme deficiency or parasitic component. While glands are inflamed, natural anti-inflammatories such as curcumin and proteolytic enzymes can be very helpful in reducing pain and discomfort.
Rule Out Any Trauma to the Anal Glands
While many groomers offer anal gland expression as part of their regular services, routine expression of healthy anal glands isn't necessary or advised. Further, it's unpleasant for dogs and potentially harmful. If the sacs are overhandled, it can lead to trauma that interferes with their function.
Anal glands were designed to function optimally without assistance. Pinching healthy glands causes tissue damage and inflammation, which in turn causes swelling. Swollen glands can obstruct the exit duct through which the fluid is expressed. If blocked secretions build up and thicken in the glands, it can lead to impaction and anal gland infection. So dogs can have perfectly functioning anal glands until an unwarranted squeezing creates a problem.
Owners should avoid expressing their dog's anal sacs "just because." There's no need for routine gland squeezing, which opens the door for future gland issues. Even veterinarians sometimes express anal glands unnecessarily if a pet is in for another procedure. If you're visiting your vet because your dog is scooting his butt along the ground, your vet may immediately express her anal glands. However, this doesn't get to the root cause of the problem, as your dog shouldn't require manual anal gland expression often, if at all, unless there's a congenital gland defect.
In some cases, it's possible that your dog's anal gland issues are due to structural, from-birth placement issue, particularly if the glands are located very deep inside their rectums. As stool collects in the colon, the pressure should cause the glands to empty, but if a dog's anal glands aren't adjacent to where the greatest amount of pressure builds in her large intestine, they won't express properly.
This is the rare situation that may require surgery to correct because the location of the glands is dictated by genetics. In most instances, however, the cause of anal gland issues is linked to environmental factors like diet or trauma. Be sure to identify the underlying cause instead of just covering up the symptoms by manually expressing the glands.
Sometimes manually infusing the glands with natural lubricants or herbal preparations can help return them to normal function. A combination of dietary adjustments that correct loose stools and natural GI anti-inflammatories is usually helpful to restore anal gland health.
