Both good and bad bacteria can live inside the gastrointestinal tract of dogs. Probiotics are the good or friendly bacteria (and yeast) needed in the gut for healthy digestive and immune system function. Dr. Judy Morgan, a public speaker on pet health and an integrative veterinarian, who offers online consultations, says probiotics combat the bad bacteria and are the gatekeepers that stop pathogenic intruders. They keep the mucosal gut lining healthy so that the body can receive nutrients.

When your dog has vomiting and diarrhea, there’s a good chance these live microorganisms in his or her gut are off balance — with more bad bacteria than good. That’s why probiotics for dogs are often a good idea when there are digestive troubles.

Dr. Angie Krause, of Boulder Holistic Vet in Colorado, says she recommends probiotics for all dogs because balanced bacteria in the gut is key to a healthy pup.

Dr. Morgan says 80 percent of immune health in the body comes from the gut. She gives probiotics to her dogs on a routine basis and rotates them.

Probiotics come in the form of supplements available for purchase and there are natural probiotics for dogs in the form of probiotic-rich foods like kefir and fermented vegetables.

Are probiotics good for dogs?

In most cases, probiotics are a great idea for dogs. Dr. Morgan says an exception is for dogs with severe intestinal or liver infections, who may not benefit from the probiotics until the infection is cleared. In this case, consult a veterinarian. She adds that occasionally dogs will get diarrhea or loose stools when given probiotics. This could be from the gut bacteria transitioning over as it regains proper balance. If it lasts more than 24 to 48 hours, stop using the probiotic.

For dogs with food sensitivities, read the supplement label’s inactive ingredients to make sure there are no unwanted ingredients. For example, avoid a supplement with chicken meal powder if your dog is sensitive to chicken.

When probiotics can help dogs

Besides providing a general health boost to dogs, there are specific situations when probiotics can help. Dr. Morgan says you can give probiotics to dogs:

• any time there’s gastrointestinal upset (like vomiting and diarrhea)
• when a dog undergoes a surgical or anesthetic procedure
• during stressful times like a trip to the groomer, boarding at a facility and during travel
• when there’s a change to your dog’s diet
• when your dog needs to take a course of antibiotics. 

Give probiotics to dogs during antibiotic use and for at least two to three weeks after the antibiotics course is finished, advises Dr. Morgan. This is because the antibiotics are killing all the bacteria in the gut — both good and bad — while they are taken.

Dr. Krause recommends probiotics for almost any health condition, including digestive issues, cancer, autoimmune disease and allergies.

Other conditions probiotics may help with include dental disease and recurring urinary tract infections by potentially balancing out the bad bacteria in the mouth and vaginal areas. Arthritis may also benefit because of probiotics’ anti-inflammatory effects. Even anxious dogs might benefit from probiotic use. Purina Pro Plan Veterinary’s Calming Care supplement contains a strain of probiotic (BL999) that may help with anxiety in anxious dogs.

Senior dogs can also benefit from probiotic supplementation, says Dr. Morgan, because they tend to struggle with diminished immune health and more chronic inflammatory diseases that a healthy gut can help improve. She says for dogs who are anemic or who eat stool or soil, use a soil-based probiotic or one that contains humic and fulvic acids.

How should I give my dog probiotics?

It’s pretty safe to start giving your dog probiotics — unless there’s a specific health issue you are concerned about, of course.

There are many good probiotics on the market and also many not-so-good products. Since probiotics are live bacteria, their handling is very important. The supplement should not be exposed to high heat during storage or transport because this will kill the live bacteria. Many products need refrigeration after opening or even during shipment and storage. It’s key to know how the product has been stored.

When buying a probiotic, look for a manufacturer with a reputation of making quality products. Dr. Morgan says the probiotic’s colony forming units (CFU) should be listed on the label and in the billions. Also look for a supplement with multiple strains of bacteria rather than just one or two. She says multiple strains of Lactobacillus and Bifidobacterium along with Streptococcus thermophilus are ideal.

Dr. Krause says probiotics are difficult to overuse. It’s possible to cause stomach upset with very high doses, but also unlikely. In order to avoid giving too much probiotics to dogs, Dr. Morgan recommends not giving multiple products at the same time and rotating instead.

Natural probiotics for dogs

Dogs can also obtain probiotics naturally through food sources. Dr. Morgan says fermented foods such as kefir, fermented goat’s milk and fermented veggies like kimchi are all great sources of natural probiotics for dogs. She does caution that kefir from the grocery store that has been pasteurized and then fermented is not the best choice. Making your own fermented veggies is a very inexpensive and better way to provide good gut bacteria for your dog.

Dr. Krause says that making your own fermented foods at home will have higher counts and more variety of beneficial bacteria and yeast. Though she does warn that while fermented foods yield better results in her practice for some dogs, she has encountered others that are too sensitive for fermented foods and do better with a commercial probiotic supplement.

Proper dosage of probiotics for dogs depends on whether it is a supplement or not. If it’s a supplement, Dr. Morgan says to simply follow the label instructions. But if it’s natural probiotics for dogs, follow the recipe guidelines. If ever in doubt, start with a very small amount and monitor your pet. 

Dr. Krause offers instructions on her website on how to make fermented berries for pets using blueberries, honey and a vegetable culture starter. Her feeding instructions say to give them as a treat or with meals starting with one blueberry on food twice daily for small dogs, two for medium dogs and three to four for large dogs. She says to increase the amount gradually but stop and consult your vet if there’s diarrhea or vomiting.

What about prebiotics for dogs?

If you’ve previously heard of probiotics, you might have also heard the term “prebiotics.” Prebiotics are fiber sources, such as inulin or larch arabinogalactan, that actually feed the probiotic bacteria. Dr. Morgan says that giving them together ensures the probiotic bacteria will grow, multiply and thrive.

While technically not necessary, probiotics are a very healthy and highly recommended addition to any dog’s diet. If there’s a specific condition you are concerned about, you can check with your vet first — but generally speaking, probiotics for dogs are pretty safe.