Probiotics for Dogs and Cats: What Are They and How Do They Help?

Written by Dr. Karen Shaw Becker
safe for pets
Probiotics for Cats and Dogs

Story at-a-glance -

  • Probiotics are beneficial strains of live microorganisms that help maintain healthy levels of gut-friendly bacteria in your pet’s digestive tract
  • Kefir, yogurt and fermented vegetables are all excellent natural sources of probiotics that you can add to your cat’s or dog’s diet
  • When looking for the best dog probiotics, you have to consider three major factors
  • Probiotics and prebiotics are completely different from each other

Just like you, pets can benefit from a healthy gut microbiome. Your pet’s digestive tract is the largest immune organ in their body, and it contains even more intestinal bacteria than yours does. There are many factors that can disrupt the ratio of good-to-bad bacteria in your pet’s gut, including:

  • A biologically inappropriate diet or genetically engineered foods
  • Vaccinations
  • Emotional stress caused by change in routine or environment
  • Consumption of nonfood items or contaminated water
  • Sudden change in diet
  • Gastrointestinal (GI) disease

One of the ways to ensure that your dog or cat has a healthy population of bacteria in their GI system is by providing them with probiotics. Coined after Greek words that mean “for life,” probiotics are beneficial strains of live microorganisms that help maintain healthy levels of gut-friendly bacteria in your pet’s digestive tract, preventing pathogenic bacteria from taking over.

Various Benefits of Probiotics for Dogs

One of the first things that dog owners ask about pet probiotics is, “What exactly do probiotics do for dogs?” By reestablishing a balanced ratio of good-to-bad bacteria in your dog’s gut, probiotics may help support a variety of essential physiological functions like digestion, nutrient absorption, vitamin synthesis and toxin removal. Holistic and conventional veterinarians have also used probiotic therapy to help ease:

  • Diarrhea — Several studies have shown that probiotics may be useful for managing the symptoms and decreasing the duration of diarrhea in dogs. It may also help lower the incidence of acute and diet-related canine diarrhea.1,2,3
  • Allergies — Probiotics are known to have anti-inflammatory properties that may help alleviate the symptoms of skin allergies in dogs.4 A study published in the journal Veterinary Immunology and Immunopathology also suggests that exposure to probiotics early in life may help lower a dog’s risk of atopic dermatitis.5
  • High cholesterol levels — A study published in the journal Folia Microbiologica shows that oral administration of probiotics may help reduce high levels of serum cholesterol in healthy dogs as well as dogs with gastrointestinal issues.6

Additionally, probiotics may help reduce levels of fecal bacteria, improve vaccine response and promote growth rate in puppies.7 It may also help protect your pet against leaky gut syndrome, a condition that increases the permeability of their intestinal wall, making the GI tract incapable of keeping nutrients and good bacteria in and harmful bacteria out.8

Learn About the Benefits of Probiotics for Cats

Some benefits of probiotics mentioned above are not exclusive to dogs — they’re applicable to cats as well. According to a 2006 study published in the American Journal of Veterinary Research, probiotics may provide systemic and immunomodulatory effects in healthy adult cats.9

A study conducted by the College of Veterinary Medicine and Biomedical Sciences of the Colorado State University also evaluated the effects of the probiotic Enterococcus faecium on the incidence of feline diarrhea. This study involved 217 cats, which were divided into two groups — one group was fed a probiotic, while the other group was fed a placebo.

Results show that the percentage of cats with diarrhea was significantly lower in the probiotic group compared to the placebo group, which suggests that probiotic may be beneficial for relieving diarrhea and other inflammatory bowel diseases (IBD) in cats.10

The benefits of live microorganisms in cats with chronic diarrhea are also supported by a study published in the Journal of Feline Medicine and Surgery, which states that around 72 percent of owners noticed an improvement in their cat’s diarrhea after 21 days of probiotic therapy.11

In a separate study also published in the Journal of Feline Medicine and Surgery, researchers found that probiotic therapy may help reduce the incidence of feline herpes virus 1 (FHV-1) infection, an extremely common feline disease that may lead to recurrent ocular and respiratory symptoms.12

How to Find the Best Probiotics for Pets

As a pet owner, you’d want to find the best probiotic for your pet. However, not all probiotics are created equal. A 2011 study published in the Canadian Veterinary Journal shows that out of 25 commercial pet probiotics, only four met the expected bacterial numbers listed in their label, while only two brands properly described their contents.13

These poor results indicate there are still deficiencies in some veterinary probiotic quality. So what are the qualities that you should look for to find the best probiotic for your pet?

Choosing the Best Probiotics for Dogs

When looking for the best dog probiotics, you have to consider these three major factors:

  1. The number of beneficial bacterial strains that your dog needs — It’s best to choose a pet probiotic that provides 10 or more strains of bacteria that are beneficial for pets to promote optimal health.
  2. The amount of good bacteria that a product provides per gram — Every scoop should have at least 20 million beneficial bacteria to adequately colonize the intestines.
  3. The viability, potency and purity of the pet probiotic — Choose a product that meets or exceeds the Good Manufacturing Practice (GMP) requirements to make sure that it’s safe, potent and not contaminated.

Moreover, make sure that you choose a product that’s easy to give to your dog and remains stable under normal storage conditions.

How to Find the Best Probiotics for Cats

When choosing the best probiotics for cats, you also have to consider the factors mentioned above. Take the time to read the product’s label to make sure that it contains the correct strains and amount of bacteria that are beneficial for pets and not for people, since probiotic formulas developed for humans are not appropriate for cats or other companion animals. Remember to choose a form of probiotic that’s easy to administer in case your cat doesn’t like being given supplements.

Some Healthy Foods Provide Natural Probiotics for Dogs and Cats

If you’re a long-time reader of Healthy Pets, you know that I recommend giving pets the majority of their nutritional needs though a fresh, whole food diet that is nutritionally balanced and species-appropriate. This is why I suggest that you consider adding these natural sources of probiotics to your dog’s or cat’s diet:

  • Kefir — Made from the mixture of raw milk and live cultures of beneficial yeasts and bacteria called “kefir grains,” this fermented beverage contains around 10 to 20 strains of probiotics. Adding this into your pet’s diet is one of the best and least expensive ways to up their probiotic intake.

    You can make kefir at home by simply adding a half packet of kefir starter granules to a quart of raw organic milk. Allow the mixture to ferment at room temperature overnight, and then strain the kefir into a clean container. Add 1 to 3 teaspoons of kefir to your pet’s food once or twice a day for optimal GI health.

  • Fermented vegetables Traditionally cultured veggies contain a wide variety of beneficial bacteria, potent chelators and detoxifiers, and various vitamins and minerals. Together, these powerful substances may help boost your pet’s immunity and protect them against diseases. Fermented vegetables are available at groceries (make sure it’s onion-free), but it’s cheaper and easier to make your own at home.

    When adding it into your pet’s meals, start with small amounts before gradually increasing the serving by a teaspoon or two per day. Keep in mind that feeding too many fermented veggies all at once may cause your pet to experience GI upset.

  • Grass fed plain yogurt — Yogurt has long been known as an excellent source of beneficial probiotics. Aside from live cultures, it can also provide your pet with calcium, B vitamins and cancer-fighting conjugated linoleic acid (CLA). If you’re planning to buy yogurt, choose a brand that’s organic, unflavored and made from pastured milk. Better yet, make your own yogurt at home using a starter culture and raw grass fed milk.

Commercial Pet Food With Probiotics: What You Need to Know

Because of the increasing popularity of pet probiotics, many pet owners have been looking for commercial pet foods claiming to contain these beneficial microorganisms. Before you buy one of these highly processed commercial pet foods, let’s take a closer look at the truth behind their claims.

Is Commercial Dog Food the Best Source of Probiotics for Dogs?

In order for probiotics to do their job in your pet’s digestive tract, they must be alive and able to reproduce. However, probiotics are sensitive to heat and moisture, so if these microorganisms are added to pet foods preproduction, then the manufacturing process will kill off most of them and will render them useless.

A study published in The Canadian Veterinary Journal shows that out of 19 commercial pet foods tested for their probiotic claim, not one product contains any of the listed microorganisms on their label.14 That said, if you want to provide your dog with the foods or treats that are rich in probiotics, it’s best to feed them natural sources of these organisms like the ones listed above.

Is Probiotic Cat Food Worth the Money?

The manufacturing process involved in the production of cat food also renders gut-friendly bacteria useless. Hence, cat foods that claim to contain probiotics are a waste of money. In fact, in the study mentioned above, six out of the 19 tested commercial pet foods that didn’t meet their nutrient claims are made for cats.

Pet Probiotic Supplement: Another Ideal Option

If your pet is the kind to eat any food you give them, then feeding them fermented veggies, yogurt or kefir shouldn’t be a problem. However, if they refuse to eat these natural sources of probiotics, then you may consider giving them a probiotic supplement.

What to Look for in a Dog Probiotic Supplement

Dog probiotic supplements are administered orally. In case your dog won’t swallow pills, you may opt to mix their meals with a probiotic powder, paste or solution. These supplements also contain different strains of bacteria that perform different functions,15 so it’s important for you to know which strains are most beneficial for your pet. For example:

  • Bifidobacterium lactis — Helps stimulate immune responses
  • Bifidobacterium animalis — Helps protect the GI tract and promote overall well-being
  • Lactobacillus acidophilus — Helps keep your pet’s entire digestive tract in healthy condition
  • Bifidobacterium longum — Helps maintain optimal digestive function and improve immune health
  • Bifidobacterium bifidum — Helps promote balanced gut microbiome
  • Lactobacillus casei — Helps promote the growth of gut-friendly bacteria

Aside from looking for the strains mentioned above, don’t forget to check the product’s colony forming units (CFU). Choose a probiotic with the highest CFU to make sure that you give your dog a diverse array of beneficial organisms in just one dose.

What to Look for in a Cat Probiotic Supplement

Probiotic supplements for cats are also available in a variety of forms, such as powder, pills, paste or solution, which you can easily mix in their meals or hide in a treat.16 Be sure to give your cat a supplement that offers a diverse array of probiotic strains, including the ones mentioned above. To administer a dosage, follow the instructions on the supplement’s packaging, or consult your holistic veterinarian to determine the specific dose that’s suitable for your pet.

Pet Probiotics Side Effects: Are There Risks to Consider?

As a pet parent, it’s your responsibility to make sure that your pet consumes safe and high-quality foods. I recommend that you also practice the same precaution when giving your pet supplements. One of the things you need consider before adding any supplement into your pet’s diet is the potential side effects that it may cause. The good news is that probiotic supplements generally do not have any severe negative effects in pets.

Side Effects of Dog Probiotics

Dog probiotics are generally regarded as safe because they only contain living organisms that are already found in your pet’s gut. Hence, there aren’t many side effects associated with dog probiotic supplements. If you’re going to feed your pet fermented vegetables, then it’s best to start with small amounts before gradually increasing the serving to allow your dog’s digestive system to adapt. Feeding them too much fermented veggies may lead to upset stomach.

Cat Probiotics Side Effects

As with dogs, probiotics for cats rarely cause side effects. The guidelines for feeding fermented vegetables for cats is also the same — start feeding small amounts to avoid GI upset before increasing the serving by 1/2 teaspoon. Many cats will not consume foods that naturally contain probiotics, so most cat parents resort to using kitty-friendly probiotic supplements.

Be Careful Not to Confuse Probiotics With Prebiotics

Although they sound similar, probiotics and prebiotics are completely different from each other. Prebiotics are nondigestible food ingredients in the form of complex sugars, including fructooligosaccharides (FOS), inulin and oligofructose.

Many commercial pet food manufacturers claim their products contain both prebiotics and probiotics. Some brands also claim that prebiotics help nourish friendly bacteria, but this isn’t always the case. Prebiotics can cause growth of pathogenic bacteria and be harmful for pets with yeasty guts. Unlike probiotics that can help alleviate diarrhea and other IBDs, prebiotic supplements may exacerbate GI issues in pets.

If you really want to give your pet prebiotics, I recommend that you get them from natural sources like asparagus, apples, bananas and artichokes. In my opinion, if you already feed your pet a balanced diet, you no longer need to give them prebiotic supplements.

Frequently Asked Questions (FAQs) About Pet Probiotics

Q: Can I give my dog human probiotics?

A: While there are no studies to prove that human probiotic supplements can harm dogs or other companion animals,17 I recommend that you avoid probiotics that are formulated for human use because they do not contain strains of bacteria that match your pet’s microbiome. Instead, choose a probiotic that’s specifically formulated for pets.

Q: What sources of probiotics can I give to my cat or dog?

A: Kefir, yogurt and fermented vegetables are all excellent natural sources of probiotics that you can add to your cat’s or dog’s diet. If your pet refuses to eat these foods, you may opt to give them a probiotic supplement.

Q: Are probiotic supplements safe for cats and dogs?

A: Yes, probiotic supplements are generally safe for pets, as they contain microorganisms that are already present in your pet’s gut.18

Q: How long do probiotics take to work in dogs?

A: Probiotics may help repopulate good bacteria as soon as it enters your pet’s gut, but it may take several hours or days for you to see noticeable results. For example, when used in the management of acute canine gastroenteritis, probiotics won’t stop diarrhea simultaneously. Rather, it may help reduce the duration of diarrhea to 1.3 days instead of 2.2 days.19

Q: Can dogs eat probiotic yogurt?

A: Yes, dogs can eat yogurt as long as it doesn’t contain flavorings, excessive sugar and xylitol, an artificial sweetener that’s toxic to dogs. If you want to provide your pet with safe, probiotic-rich yogurt, consider making your own.20

Q: What are some nondairy probiotics sources for dogs and cats?

A: If your pet has a hard time digesting dairy sources of probiotics like yogurt or kefir, then I suggest giving them fermented vegetables along with their meals.

Q: My dog ate a bottle of probiotics. What should I do?

A: While probiotics do not usually cause side effects, it’s still best to seek medical advice immediately in case your pet eats the contents of a bottled probiotic supplement. Take your pet to the vet, and don’t forget to bring along the labeled bottle of probiotics that they consumed.