Our editors independently research, test, and recommend the best products; you can learn more about our review process here. We may receive commissions on purchases made from our chosen links.
Best Overall: Purina Pro Plan Veterinary Supplements FortiFlora for Cats
Purina’s take on probiotics is a savory-tasting powder that’s easy to mix into your cat’s food and packed with beneficial bacteria to promote gut health and support immunity. The supplement contains 500 million live microorganisms and is a great choice for cats who tend to struggle with diarrhea and other digestive issues. Its formula also includes vitamin E, vitamin C, and beta-carotene for additional immune system support. It can be purchased in 30 and 80-count packets and consists of 43% protein, 10% fat, 1% fiber, and 5% moisture.
Customers write that they were at their wit’s end after dealing with their cat’s diarrhea and digestive issues, but Purina’s FortiFlora supplement made an incredible difference in their pet’s intestinal health. The flavor wins over cats, too—while many probiotics are flavorless, felines seem to like the taste of this powder enough to lick it off their bowls.
Best for IBD: DrFormulas Nexabiotic Probiotics for Cats Diarrhea Treatment Supplement, 30 Doses
If you’re specifically looking to support a cat with feline inflammatory bowel disease, this supplement includes a combination of 23 probiotics formulated to help treat symptoms like diarrhea and constipation. The blend of bacteria strains contains 17 billion CFUs, or colony-forming units (the number of live microorganisms in each serving). The supplement itself is an easy-to-open capsule that can be emptied into your cat’s food or water and is completely flavorless.
Customers write that Nexabiotic supplements worked wonders for their cats with IBD. It contains the bacteria Saccharomyces Boulardii, which has a positive effect on gastrointestinal health, and successfully helps to curb IBD symptoms like diarrhea and vomiting. Buyers report their cats are eating better, sleeping more comfortably, and seem overall happier since starting on the supplement.
Best Powder: TOMLYN Pre & Probiotic Water Soluble Powder Cat Supplement
Powder-based probiotics are the easiest to add to your cat’s meals or water bowl, quickly absorbing without adding any medicinal flavor that might discourage your pet from consuming them. This supplement from Tomlyn contains over four billion CFUs per packet, supporting digestive and bowel health by maintaining balanced microbial flora in your cat’s gut. The formula also includes prebiotics to support positive bacterial growth. It's flavorless, odorless, and easy to digest.
Tomlyn Pre and Probiotic Supplements set cats’ digestive systems right, firming up loose stools and settling sensitive stomachs. Some reviewers note that it can be helpful if your cat has recently taken a course of antibiotics, which can kills off the good bacteria in the digestive system along with the bad.
Best Pill: VetriScience Laboratories Vetri-Mega Probiotic Digestive Health Dog & Cat Capsules
These easy-to-swallow capsules contain eight different strains of probiotic bacteria, with a total of five billion microorganisms per dose. These particular probiotics also help with gas and bloating, and keep your cat's bowel movements regular. Give it to your cat as a half-capsule, ideally sprinkled over their food (the supplement itself is flavorless). Since it’s also dog-friendly, it’s ideal for multiple-pet households.
Customers have reported success using VetriScience’s capsules with both adult cats and kittens, reducing gas issues and restoring their pet’s appetite. It’s also had a positive effect on cats who experience vomiting and diarrhea, making it an all-around great choice for maintaining a healthy gut.
Best Liquid: The Honest Kitchen Instant Goat's Milk with Probiotics
For a dose of probiotics your cat can lap up like a drink, we love the Honest Kitchen’s Instant Goat’s Milk. This natural goat’s milk is packed with added probiotics and digestive enzymes to support gut and immune health. Just mix it with water, and it can be served as a drink or poured over food, giving your cat the benefit of over 5 million active cultures. The milk comes from pasture-raised goats and is both shelf-stable and human-grade, and consists of 35% protein, 1% fat, 0.5% fiber, and 10% moisture.
The Honest Kitchen’s Instant Goat’s Milk has a marked positive impact on cats dealing with diarrhea, vomiting, and even kidney issues, according to reviewers. Cats enjoy it whether it’s served by itself or mixed with food—and some owners report it has helped restore appetites and assisted with healthy weight gain for cats with sensitive stomachs.
Best Gel: PetAg Bene-Bac Plus FOS & Probiotics Gel Supplement
Gel products like PetAg’s Bene-Bac supplement offer another way of introducing probiotics to your cat’s system. It comes in an easy-to-dispense syringe, allowing you to squeeze a drop onto your finger for your pet to lick off (alternately, just put it in their food). The product contains 20 million CFUs per gram, relieving intestinal stress through its inclusion of lactic acid-producing bacteria. While it’s designed to be simple to use with newborn animals (who are born without bacteria in their GI tract), it’s just as useful for adult animals.
Best Digestive Enzymes: NaturVet Advanced Probiotics & Enzymes Plus Vet Strength PB6 Probiotic
Digestive enzymes are another method of supporting your pet’s digestion and helping them break down foods. This NaturVet supplement provides the benefits of digestive enzymes with the power of probiotics (as well as prebiotics). It can be used with cats over the age of six weeks—just add a quarter-teaspoon to their wet or dry food. If your pet struggles with gas, has a sensitive stomach or experiences issues breaking down certain foods, these digestive enzymes can make a difference (while the added probiotics further promote gut health).