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Probiotics for Dogs: Helpful or a Passing Health Fad?

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It doesn’t matter what the health trend happens to be – as soon as we incorporate it into our routine, it hits the pet industry. And there’s a rough kind of logic at work. If something’s good for us, it must be good for our cats and dogs. Sometimes the theory pans out. Other times, though, we end up causing our beloved furry companions problems. As such, you might wonder where probiotics for dogs fall on the fad list. Before you start mixing a daily dose of yogurt into your pup’s food, make sure you have all the information.

The Magical Microbiome

Most people can name the major organs found in the body. Maybe you’ll miss a few of the smaller, lesser-known entities (especially if you don’t know the purpose – appendix, anyone?). But how many people list the microbiome? The microbiome contains all of the bacteria in the body – about 10 strains per cell.

In a human, the microbiome weighs FOUR pounds – twice that of the liver!

Most of the microbiome lives in the gastrointestinal tract. And, primarily, they hang out in the colon. Known as commensal bacteria, they snack on the same foods you (or your dog) ingest. (Convenient, right?) And the byproducts of that bacterial digestion offer the body helpful benefits.

So long as the bacteria stay where they belong, anyway.


Everyone – whether human, dog, cat, or reptile – totes around a load of commensal bacteria in their gut. It sounds gross, but those friendly bacteria help the body out. All of those pounds of bacteria mean there’s less room for pathogenic bacteria (UNFRIENDLY bacteria that cause disease). The microbiome also produces short-chain fatty acids (SCFAs). SCFAs function throughout the body: in metabolism, immune responses, and endocrine pathways. (Not too shabby for a few simple-celled organisms!)

For all mammals, the microbiome consists of bacteria in the following 6 phyla:

  • Actinobacteria
  • Bacteroidetes
  • Firmicutes
  • Fusobacteria
  • Proteobacteria
  • Spirochaetes

And within those phyla? THOUSANDS of strains of bacteria. All trying to stay in perfect balance, so you and your dog stay happy and healthy.


So, where do probiotics for dogs come in? Probiotics represent live colonies of bacteria. And they represent one of the newest health fads in the animal world. However, alongside coconut oil, essential oils, and CBD oil, some pluses and minuses come with this trend. And before you rush to join the craze, you need to understand the risks.

Veterinarians have turned to probiotics for dogs in the past to help reset the GI tract for pups affected by stress or lengthy antibiotic treatment. (Antibiotics are often broad-spectrum, taking out ANY bacteria they encounter) However, vets monitor the dogs, set a specific time limit on dosing, and choose the product with care. Because TOO MANY bacteria in the gut – even friendly bacteria? It’s NOT a good thing.

The Cautions of Probiotics for Dogs

The problem with the microbiome is it rests on a delicate balance. If those little bacteria decide to overgrow, they can release toxic byproducts into the GI tract. Then your dog ends up with leaky gut syndrome. Instead of the intestines keeping fluids and nutrients inside, EVERYTHING seeps out. And some of the bacteria in the colon should NEVER enter the bloodstream.

Reaching for probiotics for dogs when your pup’s happy and healthy can disturb the careful structure in your dog’s system. Rather than helping, you may CAUSE GI upset. And problems with the microbiome lead to complications:

  • Autoimmune disorders
  • Cardiovascular disease
  • Diabetes
  • Obesity

Remember, those bacteria have a hand in helping out with the entire body. So a tipping point in ONE thing can lead to a landslide somewhere else.

Before starting probiotics for dogs, talk to your veterinarian. They’ll let you know whether your pooch needs them, and they can help you choose the best option. (Not to mention helping you monitor your kiddo for possible negative reactions)

Understanding Probiotics for Dogs

When it comes to probiotics for dogs, you’ll find three different categories of bacteria:

  • Dairy-based strains: Lactobacillus and Bifidobacterium
  • Yeast: Saccharomyces boulardii
  • Soil-based strains: Bacillus and Enterococcus

Yeah: long, complicated names. You’ve probably seen some of these on your yogurt, supplements, or even your multivitamin. Each category comes with special advantages (and a few disadvantages).

Dairy-Based Probiotic Strains

Surprise, surprise, these bacteria come out of milk products. Most of them then require refrigeration for proper health, which is why they’re popular in yogurts. Unhappily, they’re also fragile bacteria, rarely surviving more than 24 hours in the digestive process. It doesn’t sound long, but a day can help resolve minor tummy wobbles. These are also hypoallergenic microbes, working for dogs with any particular food allergy.

The downside? Dogs are lactose-intolerant. So while it sounds like a brilliant idea to use yogurt as a probiotic for dogs, you’ll end disturbing their GI tract before you help it.

Yeast Probiotic

It sounds weird to list a yeast in the probiotic category, but Saccharomyces boulardii works in the gut nicely. And since it’s not a bacteria, it’s antibiotic-resistant. This makes it popular to protect the microbiome for dogs undergoing antibiotic treatment.

However, it’s also known to alter signal pathways in the immune system. This means if your dog ends up with an abundance of yeast, inflammation can get out of control. As always, balance is key – and, unhappily, you can’t see what’s going on inside your dog.

Soil-Based Probiotic Strains

Does “soil-based” or “spore-forming” sound better? These bacteria represent the sturdiest group. They survive digestion inside of a hard outer coating. The shell also protects them from most antibiotics. And they’re hypoallergenic, with longer survival than the dairy-based probiotics. You’ll also find strains that boost antioxidants.

However, the spore-forming group also contains strains known for causing disease. And Bacillus subtilus? It helps MAKE antibiotics. So an overgrowth can wipe out other parts of the microbiome!

Balancing Act

These are the same bacteria species you find in a human microbiome. And a cat microbiome. Or a horse microbiome. What sets everyone apart? The number and combination of the individual bacteria! And what one dog’s microbiome looks like WON’T match another – even if they’re the same breed. Not even two littermates share the same microbiome!

Starting probiotics for dogs can be a risky gamble. Are you using the right bacteria? What about the right numbers?

A tilt in one direction or another could lead to one sick pup. This is why a check with your vet is ALWAYS necessary. The last thing you want to do is aim to do good and end up causing harm.

"Veterinary probiotics are less regulated than drugs. There's less confidence that you are getting what the label claims."

~Joseph Bartges, DVM, PhD, DACVIM, DACVN

Choosing a Probiotic for Dogs

When you start considering probiotics for dogs, you find them EVERYWHERE. They pop up in treats, food, powders, and everything in between. However, you need to think through things carefully. Not every probiotic is created equal. As a pet supplement, there’s NO regulation of probiotics. You need to do your research to make sure you’re protecting your dog. You also need to keep some important factors in mind:

  • NASC Seal: The National Animal Supplement Council (NASC) oversees probiotics for dogs. If you note the seal on a product, you can breathe easier.
  • Strain Identification: You know there are different categories of probiotics. And every strain does something different. You should see a list of the strains on the package label. And while a long list looks more impressive, the most effective scientific trials come from single strains. When you start combining strains, they often compete with each other.
  • Guaranteed Analysis: Bacteria are living creatures. And, over time, they start to die. Even the soil-based strains have a shelf life. The package should guarantee how many bacteria will be alive by the time you finish the package.
  • Expiration Date: Nothing lasts forever, especially live cultures. If your probiotic promises it’s good for years on end, you need to question the efficacy.
  • Packaging: Microbiome bacteria? They live in the gut – an environment devoid of oxygen. This means probiotics for dogs should come in capsules or individual packets that protect them from the outside air. Tubs will kill off the strains inside faster, leaving you with…well, yummy powder?

Understanding CFUs

Probiotics for dogs get measured in colony-forming units (CFUs). Not all of the bacteria you start with will survive to reach your dog’s colon. Some die sitting on your shelf (especially if they aren’t packaged properly), and some end up destroyed during digestion. How many CFUs you’re looking for depends on the strain. After all, some probiotics are sturdier than others.

  • Dairy-based strains: 10 billion CFU
  • Saccharomyces boulardii: 0.5-5 billion CFU
  • Soil-based strains: 1 billion CFU

Handling Probiotics for Dogs

Once you choose the probiotics for dogs you feel works best, you need to take care of them. Improper handling results in a supplement that probably tastes good, but it’s not more than a flavored topping for your dog’s food. (In the case of treats, they’re empty calories)

You’re handling live cultures, and if you don’t care for them, they’ll die.

  1. Probiotics for dogs need to stay in a cool, dry place. If you’re coming home from the store in the middle of summer, DON’T leave them in the car. Every bacteria will die within minutes.
  2. Keep the package closed until you’re ready to use it. Remember, oxygen is NOT a probiotic’s friend!
  3. Once you hit the expiration date, throw it away and buy a new one. The bacteria are dead and useless.
  4. Discuss dosing with your vet. You CAN overdo it!

Best Probiotics for Dogs

You want to do the best for your dog. There’s nothing wrong with that. However, probiotics for dogs may or may not fall within that category. If you think your dog may benefit from the supplement, talk to your vet. They’ll help you make the best decision.

Bacteria are tricky little microbes, and they have the potential to run amok in the body. And fixing THAT problem can turn into a tangled mess.

Amazing Naturals combines a probiotic for dogs with a joint supplement. It’s a nice option for people with senior dogs in need of glucosamine. You get 7.5 billion CFUs of Lactobacillus in addition to the glucosamine and chondroitin, all in a delicious bacon and liver treat. (What dog doesn’t love bacon and liver?) There’s no corn, egg, wheat, soy, or gluten, and that dairy-based bacteria won’t inflame allergies, either.

Downsides? For a dairy-based strain, you come up short on the CFUs. The treat also offers no protection against oxygen, which means your dog won’t see any probiotic benefit within a few days. (Lactobacillus is too delicate to survive so much exposure to air) It’s a great joint supplement, though.

The Good

The Bad

If you want a sturdier strain of bacteria, NaturVet has the answer. They use two different strains of Bacillus in their soft chews, with 1 billion CFUs for one and 1 million CFUs for the other. There’s no wheat to trouble dogs with allergies, and the earthy taste from the brewer’s yeast appeals to most dogs. Best of all, you get that NASC seal of approval.

The downsides? Unfortunately, while the container closes, the chews still get exposed to oxygen. Bacillus is sturdy, but by the time you get to the bottom, odds are most of the bacteria will end up dead. You also need to keep an eye on the age limit: no puppies under six weeks old.

The Good

The Bad

If you’re looking to watch your wallet while hunting for probiotics for dogs, Nusentia is your best bet. Combining multiple strains of Lactobacillus and Bifidobacterium, your dog gets 1 billion CFUs per scoop. There’s no rice, soy, or dairy in the ingredients (some irony there). And while the jar holds up to 360 scoops, they warn you to use it within eight months to get the best results.

So what are the downsides? Once again, you’re getting a probiotic for dogs that gets constant exposure to oxygen. And the delicate dairy-based strains won’t stand a chance. Well before the eight-month recommendation, you’re going to scoop powder with no benefits. And 1 billion CFUs is much too low to provide your dog with usable bacteria in the first place. Finally, some people complained about the powder forming clumps in their dog’s food, causing the pup to refuse to eat it.

The Good

The Bad

In the veterinary world, Nutramax’s Proviable is a familiar friend. Each capsule contains strains of EnterococcusBifidobacterium, and Lactobacillus, with 5 billion CFUs per capsule. You have the option of popping the capsule down your dog’s throat, or you can open it and sprinkle the contents over their food. (The capsule provides additional protection to the delicate dairy-based strains, letting them reach the colon safely) They also include prebiotics, which are food for bacteria, keeping them happy and healthy in your dog’s GI tract.

Downsides? Unhappily, the CFU count comes up short for dairy-based strains. (It’s fine for the Enterococcus) And some owners complained their dogs got a little gassy with regular use. (That IS a side effect of gut bacteria!) You’ll have to decide if you can live with it.

The Good

The Bad

If you’re going to go for a health food supplement, why not combine your probiotic for dogs with superfoods? That’s PetVitalityPro’s philosophy. With antioxidants, phytonutrients (that’s the green tint, by the way), and a kick of vitamins and minerals, you’re offering plenty of health benefits in this chewy treat. And dogs adore the duck flavoring. You also get several strains of Lactobacillus with 4 billion CFUs per two chews. It’s the perfect combination of health and deliciousness.

The downsides? You guessed it – the CFUs come up short. Also, the treats fail to protect the fragile Lactobacillus from the outside air. However, the additional health benefits still make it a nice treat for your dog to snack on.

The Good

The Bad

Purina’s FortiFlora is the first name in probiotics for dogs. With solid recommendations by veterinarians and owners alike, it comes out on top every time. Individual packets contain a single strain of Enterococcus with 1 billion CFUs. The liver flavor appeals to dogs of every kind – and it WON’T interact with allergies or diet sensitivities!

We use Calming Care with our dog, which contains a special strain of Bifidobacterium (BL999) shown to promote calming behaviors in dogs. But we also use Feline FortiFlora with all three cats. And I don’t know how we lived without it. No more loose stools, fewer stomach upsets (it doesn’t work on hairballs), and the cats? They DEVOUR it!

So what are the downsides? FortiFlora’s expensive. You have to pay for those individual packages, after all. And it may not work for your dog. Remember, you don’t know what’s going on with their microbiome, so it’s a guessing game.

The Good

The Bad

VetriScience is another well-recognized label in the dog health community. They fill their probiotic for dog capsules with strains of LactobacillusBifidobacterium, and Enterococcus. Each capsule holds 10 billion CFUs and a healthy dose of prebiotics to nourish the bacteria. They also caution you to refrigerate the bottle after opening it to protect those precious dairy-based strains further. (Capsule or no capsule, they like staying chilled) And, best of all, you get the NASC seal of approval.

Downsides? Unfortunately, the prebiotic VetriScience chose was rice flour, which can irritate some dogs’ stomachs. There were also some complaints of diarrhea following the use of this probiotic for dogs, but no mention of how they stored the capsules. (And, of course, it’s possible the dogs didn’t need the probiotic in the first place)

The Good

The Bad

Sometimes your dog’s GI tract wants a little assistance. At least, that’s what Zesty Paws believes. They throw pumpkin and papaya into their chewy probiotic treats, giving your pup’s stomach some gentle coaxing. And into the mix, they sprinkle Bacillus and Lactobacillus at 3 billion CFUs per chew. Most dogs appreciate the pumpkin flavor, and the bacteria won’t mind it, either.

The downsides? Reaching that 10 billion CFU limit for dairy-based strains appears to be a struggle for probiotics for dogs. And since the Lactobacillus make up five of the six strains in this treat, it comes up short. Your dog will probably enjoy the treat, anyway, but the lack of an oxygen barrier will eliminate most of the beneficial bacteria. The pumpkin might settle an upset stomach on its own, though.

The Good

The Bad

Tipping the Scale

Probiotics for dogs get tricky. On the one hand, you’re hoping to do something beneficial for your beloved pup. And if you have a dog suffering from stress, a recent bout of illness, or a wobbly tummy, they MIGHT.

On the other hand, if you disturb the microbiome’s careful balance, you may land your dog in the hospital for an extended stay. Friendly bacteria can change their tune on a dime.

Before you decide to reach for that probiotic, sit down with your veterinarian. They know your dog’s history and what’s going on with their GI tract. Armed with all of that knowledge, they can make the best recommendations.

And stay away from the yogurt. It’s good for you, but your dog’s stomach WON’T appreciate it.

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Andria Kennedy

Andria Kennedy

Andria grew up in a pet-friendly household. On weekends, the family made trips to zoos and aquariums in the area. So it wasn’t a surprise when she gravitated toward a career with animals.

After six years working among the background operations at the Philadelphia Zoo, she gained a unique insight into the veterinary world. The vet staff provided her first lessons in terminology, the identification of medical equipment, and glimpses of radiographs (x-rays). She also enjoyed plenty of opportunities to talk with everyone, including the veterinary technicians. And they offered an alternative for someone NOT interested in surgical pathways: Namely, their course of study.

Andria enrolled at Harcum College. Philadelphia boasts two programs for vet techs, but only Harcum works with the Ryan Veterinary Hospital and New Bolton Center (University of Pennsylvania’s small and large animal facilities, respectively). Harcum’s vet tech students receive six months of hands-on teaching and experience alongside Penn’s vet students.

With the opportunities and connections available with one of the top veterinary schools, the decision was easy for her to make.

New Bolton Center: Large Animal Medicine
Andria ended up trudging through snow up to the knee and shivering in subzero temperatures during her winter semester, but she wasn’t disappointed with her choice. New Bolton provided a thorough grounding in large animal medicine. A horse-lover as a child, the experience renewed those old emotions.

And a few memories stood out and remained to this day:

  • Standing alongside a Clydesdale and feeling TINY
  • Holding the reins of a horse galloping at top speed on a treadmill
  • Nursing tiny foals through the first days of their life

Ryan Veterinary Hospital: Small Animal Medicine
Veterinary students can legally work at a practice while studying. Andria took advantage of the opportunity, gaining “real life” experience while attending class. It provided a slight advantage when she entered her three months at the small animal hospital.

However, as Ryan Veterinary Hospital offers treatments unique to the veterinary community, she continued to gain valuable experience. For instance, she spent a day working alongside their Chemo Team. The positivity of everyone she encountered – staff, clients, and patients alike – left a lasting impression.

Additional standout moments included:

  • An afternoon spent with the head of the feline kidney transplant program
  • A day serving as the anesthesia technician in their new radiation unit
  • Recognizing a radiograph of a giant elephant shrew (applying her previous zoo knowledge)

Emergency/ICU Veterinary Technician
Accompanying her Associate of Science in Veterinary Technology, Andria received a passing score on the Veterinary Technician National Exam (VTNE). The two led to her certification/license as a veterinary technician – first in Pennsylvania (CVT) and later in Virginia (LVT).

Emergency medicine appealed to her from the beginning. The flux of ailments, injuries, and even species kept her mind sharp at all times. The knowledge required to handle cats, dogs, exotics, and even wildlife is highest in an ICU setting. When a vet tech never knows the patient’s stability coming back to the treatment area, skills and the ability to respond in an instant always stay in peak shape.

With treatments evolving at a constant basis, Andria sought out the best Continuing Education opportunities. She attended the International Veterinary Emergency and Critical Care Society (IVECCS) Conference whenever possible. This allowed her to discuss the latest wound treatments, medications, and advancements in diet formulations.

Cardiology Veterinary Technician
With the increased knowledge and experience, Andria noticed gaps in her abilities. Her grasp of cardiology remained at the basic level. She wanted to boost her skills and understanding as much as possible, improving her patient care. When an opportunity within the practice arose to move into the cardiology department, she accepted.

She sharpened her ability to read ECGs, recognizing arrhythmias of every type. Speaking with the cardiologist, she learned to read echocardiograms, picking out the most common disease processes. And, courtesy of her position in the department, she took in everything she could regarding the grain-free diet concern.

And throughout her ten-year career, she built her store of client interactions. She learned stories of heartbreak and hope. In the middle of the night, she shared touching and humorous conversations. Every moment taught her to engage with people. And the skill blended into her writing ability, capturing the interest of pet-lovers everywhere.

Check out Andria’s LinkedIn here

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