Updated: Jan 23

Just like humans, the majority of a dog’s immune system resides in his gut. The gut is the largest immune organ in the body and contains approximately 70% of all immune cells. So keeping your dog’s digestive system running optimally is essential to making sure that he stays healthy, active, and lives a full and healthy life.

One way to potentially improve your dog’s digestive health is to offer him a daily probiotic supplement. There have been extensive studies on the benefits of probiotics in humans, however, veterinary research is just starting to really dive into how supplementing your pup with a variety of good bacteria can aid in keeping him healthy.

What are Probiotics for Dogs?

The World Health Organization (WHO) defines probiotics as “live microorganisms, which when administered in adequate amounts, confer a health benefit on the host.” According to American Kennel Club (AKC) veterinary expert, Jerry Klein, DVM, probiotics (bacteria or yeast) can potentially provide an array of health benefits to dogs.

“They are believed to help treat and/or prevent a variety of illnesses and diseases, especially those related to the gastrointestinal system,” he explains. They inhibit the growth and activity of harmful bacteria, such as E. coli, Salmonella, and Clostridium perfringens, as well as provide other advantages to the intestines.

Brennen McKenzie, VMD, who practices at Adobe Animal Hospital in Los Altos, California, has studied the use of probiotics in canines extensively and believes that there are definitely some benefits to dogs taking them. “In theory, if probiotics can pass through the stomach and colonize the intestines, they can have a variety of desired effects, such as preventing or treating diarrhea or improving other intestinal conditions, such as inflammatory bowel disease,” he states.

Types of Probiotics for Dogs

Probiotics for dogs come in a variety of shapes and sizes. “Some are marketed just for dogs, some for a range of animals, and some for humans (that are subsequently used in dogs),” says J. Scott Weese, DVM at the Department of Pathobiology at the Ontario Veterinary College. “These can come as pills, powders, pastes, or solutions.”

Each probiotic supplement contains one or more types of bacteria and/or yeast that can carry out a variety of different functions. For instance, certain strains, such as Bifidobacterium, are known to be helpful in slowing down the duration of diarrhea in dogs and for their overall immune boosting properties. Other types, like Lactobacillus, have shown benefits in helping dogs to increase the absorption of nutrients and to optimize their digestive systems.

Human Probiotics for Dogs?

There are significant differences in the biology of dogs and humans, including differences in the acidity of stomach fluids, digestive enzymes, and other features of the gastrointestinal tract.

Because probiotics for humans have not been designed or tested to accommodate the biology of dogs, it is impossible to know if these will be safe or effective in our canine companions. It is safer to use products designed and tested for dogs.

Human Probiotics for Dogs?

There are significant differences in the biology of dogs and humans, including differences in the acidity of stomach fluids, digestive enzymes, and other features of the gastrointestinal tract.

Because probiotics for humans have not been designed or tested to accommodate the biology of dogs, it is impossible to know if these will be safe or effective in our canine companions. It is safer to use products designed and tested for dogs.


Kefir is such a healthy and wonderful food addition to any diet, without a one can dispute the benefits of kefir, or yogurt, or cheese, or any other food containing digestive bacteria.

However, that said, please keep in mind that you can't count to feed Kefir as a Probiotic source.

I have heard people say that they feed kefir to supplement the Probiotic needs of their dogs. This statement may be true for humans.

However, dogs need a certain set of specific Bacteria that is not found in Kefir.

From 20 to 25 important bacteria, there is only two found in Kefir, Lactobacillus acidophilus and Bifidobacterium bifidum.

Remember that it is not enough that a food source to have the digestive bacteria,...they have to be specific to dog's digestive track.

One of the things that people don't realize is that there are many forms of bacteria in Probiotics...and each varies by use.

Humans, Dogs, Cats, Birds, et al, all have different kind of beneficial bacterial colony in their digestive system.

That is why when dogs consume human specific bacteria, they do get sick and although it is not life threatening, but highly uncomfortable…diarrhea, bloating, vomiting, etc.

So be vigillant when looking for new Probiotic. Read the numbers, anything below 3 Billion is not enough…Any dog specific Probiotic claiming numbers above 50 Billion, usually contains human specific bacteria. Check the list of names.

Be weary of any Probiotics that is claiming its use for multiple species..."Suitable for Dogs, cats, Birds, etc..."...there is no such thing as multi-specie bacteria.

Probiotic bacteria found in kefir products include: Lactobacillus acidophilus, Bifidobacterium bifidum, Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus helveticus, Lactobacillus kefiranofaciens, Lactococcus lactis, and Leuconostoc species.


Let's talk about that too, since it is extremely important and as beneficial as Probiotics.

Prebiotics are what feeds the good bacteria in the gut and helps maintain and multiply the numbers. Without Prebiotics the Probiotics will die off and reduce and allow yeast and other harmful toxins to take over.

There are some food elements that would contain Prebiotics and feed Probiotics and could be helpful in long run and when the animals are healthy, but it is best to choose a Probiotic that also contains Prebiotic to begin with, until the gut gains its normalcy, the Prebiotics coming from food are not much help. The examples of Prebiotics from food are:

Flax, Pea, Carrots, Ginger (helps joints too and is a mild antibiotic and works on inflammations).


It took me a lot of research to put together this list and verify the validity of each, while working on formulating our own products. The following is the List of Dog Specific Bacteria:

Lactobacillus reuteri, Pediococcus acidilactici, Enterococcus faecium, Lactobacillus acidophilus, Bifidobacterium animalis, Bifidobacterium lactis, Bifidobacterium longum,

Bacillus coagulans, Lactobacillus bulgaricus, Lactobacillus plantarum, Lactobacillus casei, Bifidobacterium bifidum, Lactobacillus fermentum, Lactobacillus rhamnosus.

Each Bacteria And Its Specific Use:

  • Lactobacillus rhamnosus: assists your pet's elimination and occasional intestinal discomfort by working to stabilize her intestinal microflora.

  • Lactobacillus bulgaricus: works with other Lactobacillus strains to provide your pet with a potential source of dietary antioxidants.

  • Bacillus coagulans: You get 38 billion bacterial "buddies" ready to help support your pet's digestive tract and promote a natural balance of bacteria to this all-important area of her body.

  • Bifidobacterium lactis: a friendly bacteria often found in yogurt that is known to help support a healthy immune response.

  • Bifidobacterium animalis: a unique bacteria that promotes optimal health and intestinal well-being

  • Lactobacillus acidophilus: supports the health of your pet's entire digestive tract.

  • Bifidobacterium longum: keeps your pet's digestive system running smoothly by supporting proper digestion and bowel health.

  • Bifidobacterium bifidum: helps promote a healthy balance of flora in your pet's intestine. What's more, this organism is especially helpful for enhancing immune response.

  • Lactobacillus casei: works with other helpful organisms and helps to encourage the growth of other "good" bacteria.

  • Lactobacillus plantarum: helps to ensure that the nutrients in vitamins and supplements are getting to your pet's cells.

  • Bifidobacterium animalis: is found in your dog’s large intestine. It helps to improve overall intestinal health, prevent inflammatory activity and infection and resolve canine diarrhea.

  • Enterococcus faecium: aids in digestion and helps to maintain a healthy mix of bacteria in the dog’s stomach. It also supports inhibitory effects against shigella, E. coli, salmonella and other pathogens.

  • Lactobacillus acidophilus: helps to promote antibacterial and anti-fungal properties in the GI tract. It also helps prevent diarrhea associated with an antibiotic. Finally, it may help reduce cholesterol levels and improve weight gain/growth in puppies and younger dogs.

  • L. fermantum, L. rhamnosus, L. saluvarius, L. reuteri, L. plantarum and L. casei: all figure prominently in populations of normal canine microbiota. Along with providing strong anti-microbial activity in the GI tract, these bacteria are also extraordinarily vigorous and capable of significantly modifying and improving inferior intestinal health.

  • Pediococcus acidilactici: is used to treat constipation and diarrhea, relieve stress and enhance immune response. It’s also known to protect the small intestine from pathogens, such as E. coli and Salmonella.