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Gut Check: Are Dog Probiotics Essential Nutrition or a Health-Food Fad?

We asked four experts for the lay of the microflora landscape.

by Elizabeth Kennedy
Updated January 31, 2022
Pomeranian stands in front of a yellow bowl of homemade probiotic yogurt
Varvara Serebrova / Adobe Stock

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I’m a sucker for food trends. The contents of my cabinets — which are stocked with maca, goji berries, and coconut water — confirm it. So when probiotics for humans became popular a few years ago, I was super into it. Indeed, “probiotics,” a broad group of over 400 microorganisms that support a robust, disease-free body, are a favorite in the human supplement world. And now, they’re omnipresent in pet stores, too. But are probiotics suitable and safe for dogs? Keep reading to get the lay of this microflora landscape — and learn whether or not probiotics are a good idea for your dog. 

What Are Probiotics for Dogs, Exactly?

Dogs (and humans) are host to hundreds of different kinds of microbes and according to Mary Ellen Sanders, PhD, an internationally recognized leader in probiotic microbiology, that’s a good thing. In the canine gastrointestinal(GI) tract, probiotics promote health by “piggybacking on the important relationship between the normal immune system and microbes,” says Dr. Sanders. More specifically, Dr. Sanders suggests that probiotics increase “the activity and numbers of immune cells (or cytokines), whose job it is to attack invading pathogens.” When the immune system senses these microbes in the gut, it launches a response. 

Probiotics can also produce antibacterial compounds called bacteriocins, which directly inhibit the body’s tolerance of pathogen growth. The plain-English version: Probiotics are the good bacteria that kick out the bad, and then make it harder for the bad actors to get back in the door. Probiotics help your dog digest their food, increase their absorption of nutrients, and boost their immune system, too.

When it comes to optimizing the use of probiotics, Dr. Robert Boyle, MD and a clinical lecturer with the UK’s National Institute for Health Research, suggests that they work best as preventive agents. “Once disease is established,” Dr. Boyle says, “it is harder for [probiotics] to compete with pathogenic bacteria and processes that have already become established in the gut.” So while your dog is healthy, it’s a good idea to get them started with a diet rich in good microflora. 

How to Incorporate Probiotics Into Your Dog’s Diet

Most over-the-counter supplements include strains of several common probiotic microorganisms — Bifidobacterium bifidum, Lactobacillus acidophilus and Lactobacillus bulgaricus, for example — but the quality of these cultures varies wildly.

Some nutritionists suggest buying only refrigerated supplements, since the shelved strains may be dead by the time you get them home. However, the University of Toronto published a study that, among other things, questioned the batch-to-batch consistency in all probiotics, and found that enthusiasm for their use “has been hampered, at least in part, by concerns about precisely how the various organisms purported as probiotics mediate their beneficial effects.” In other words, there were so many products on the market, with so many different “mechanisms of action,” that questions were raised about the efficacy of these products as a whole.

If you do buy supplements, it’s best to shop for whole-food, organic, refrigerated products. Be sure to check their expiration dates and buy from companies that provide laboratory assays or summaries of the drug potency. But are supplements your only option?

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Natural Probiotics For Dogs

It’s important to note that supplements aren’t your only option. Plenty of foods in your home contain probiotics naturally such as yogurt, kefir, onions, bananas, garlic, honey, leeks, kimchi, and Jerusalem artichokes. 

Some of these foods are not ideal for dogs though; for example, onions and large quantities of garlic are dangerous and should be avoided. Kimchi is too spicy. The jury is out on dairy products — yogurt included; it depends on the dog. Some literature contends that dairy causes digestive upset in dogs, but a better part of the home feeding community includes yogurt in their dogs’ diets.

Some pet parents, including C.J. Puotinen, author of The Encyclopedia of Natural Pet Care, are so adventurous that they feed things like lacto-fermented vegetables, such as mild homemade sauerkraut or shredded carrots with ginger. (For the brave souls who wish to try offering fermented veggies, note that fennel seed is a natural remedy for flatulence).

Ultimately, you can work in any number of ways with a supportive veterinarian to come up with a safe, nutritious regime at home that takes gut health, and therefore probiotics, into account. They may recommend green tripe, the nutrient-rich lining of the stomach of a ruminant animal such as a cow, deer (venison), or bison, which is loaded with beneficial bacteria and enzymes. Sticking with foods that are easily digested by your dog (like green tripe) makes the addition of probiotics to your dog’s mealtime routine incredibly safe.

Finding Your Dog’s Natural Probiotic Balance

So, you mindfully begin supplementing your dog’s diet, but their coat remains dull and their energy, sluggish. What could be going on? No matter how thoughtfully you supplement, the detrimental effects of kibble riddled with carbohydrates and fillers can ruin our best auxiliary efforts. 

The sugars in these foods not only fail to protect your dog from harmful bacteria, but they also nourish the very bacteria you’re trying to discourage. Dr. Jeannie Thomason, the co-founder of the American Council of Animal Naturopathy, suggests that with yeast and other harmful bacteria thriving in the gut, it’s no wonder veterinarians are seeing a rise in inflammatory bowel disease, irritable bowel syndrome, diabetes, and pancreatitis. The preservatives and synthetic chemicals in low-quality food damage the tissues of the digestive tract and flood the body with toxins.

Thomason says that a healthy, species-appropriate diet is the first line of defense against illness, and will often balance the gut naturally. “In nature, animals know to seek out those foods that satisfy their nutritional needs,” she notes, pointing to the eating patterns of free-roaming wolves. “Before eating muscle or bone, wolves feast on stomach contents, the liver, pancreas and intestines — in other words, they are gorging on enzyme-laden tissues. Wolf pups are weaned and maintained on regurgitated food, also heavily laced with digestive enzymes.”

How to Maximize Probiotics for Your Dog

Just as diet has a profound effect on a dog’s health, several factors can radically affect the extent to which probiotics are able to win the war in your dog’s GI system. For example, a dog who’s undergone antibiotic therapy needs support to recover at the microbiotic level. These therapies make no distinction between beneficial and harmful microorganisms; they destroy them all. Many experts suggest that the harmful strains, being more opportunistic, are quicker to re-colonize and exploit the body’s vulnerabilities. Travel and other environmental changes can be overwhelming, literally altering an animal’s body chemistry. 

Everyday stresses and the effects of a sedentary lifestyle throw off balance as well. Aging, while inevitable, can also influence the normal balance of microflora in the intestinal tract. Your dog depends on you to protect them from undue stress and thus, improve their chances of long-term wellness.

So it’s true — I follow trends. I give my dog homemade yogurt probiotic (she’s fine with it). I have offered her homemade fermented veggies (hence, the fennel-seed tip). And I even include green tripe in her menus from time to time. What we call fads today can become tomorrow’s conventional wisdom when they prove to be legitimate practices that advance our health and happiness. The bottom line is, it’s healthy to take probiotics into account. And judging from my dog’s response when the tripe hits the bowl, I have the happiness part covered, too.

Disclaimer alert: This article is here to share information. But, much like pineapple on pizza, the topic may be controversial. Meaning, not all vets or pet professionals agree. Because every pet is a unique weirdo with specific needs. So, don’t take this as fact or medical advice. Talk things over with your vet when making decisions, and use your best judgment (about both your pet’s health and pizza toppings).

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Elizabeth Kennedy

Elizabeth Kennedy is a freelance writer and editor in the San Francisco Bay Area.