The 7 Best Probiotics for Cats of 2021

Boost your cat's gut health with these probiotic supplements

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Probiotics for Cats

The Spruce / Chloe Jeong

Our Top Picks
This unflavored sprinkle capsule offers a variety of bacterial strains and prebiotics making it a great scientifically-backed option.
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Sold in large quantities, this unflavored probiotic is good for long-term use and has the NASC Quality Seal.
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With additional vitamins, minerals, and flavoring, this product may entice a constipated cat to eat and support it’s gut health.
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This type of probiotic has been specifically researched to support a cat’s kidneys.
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This gel provides administration instructions for all ages of kittens to make it easy to give the appropriate amount.
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The paste in this kit contains kaolin and pectin to quickly stop a cat’s diarrhea.
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This 114 day supply contains enzymes, prebiotics, and probiotics to help a cat’s digestive system.
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Probiotics are beneficial organisms to support a cat’s gastrointestinal microbiome. Certain types of bacteria are essential to a cat’s gut and if there are not enough of them or an imbalance of good and bad bacteria and toxins occurs, probiotics may be beneficial. This imbalance can occur due to dietary changes, diseases, medications, stress, and more. Probiotics may be used short term or long term to help combat digestive issues, and can be particularly beneficial to kitties who have spent time living outside.

Best Overall: Nutramax Proviable-DC

Proviable-DC Probiotic Digestive Health Supplement

Concerns surrounding the effectiveness and viability of probiotics in veterinary supplements are put to rest with Nutramax Proviable-DC. This product has a unique seven strain blend of probiotics along with two prebiotics to support gut health. It comes packaged in foil blister packs to preserve the bacteria until they are ready to be administered to your cat and does not require refrigeration. 

The entire capsule can be administered to your cat as a pill or it can be opened and mixed into your cat’s food or put in a small amount of cool water to syringe into its mouth. Unlike some other probiotic products, it has no added flavorings so you don’t have to worry about food allergies or sensitivities and has been scientifically researched for its effectiveness in felines.

Best for IBD: VetriScience Laboratories Vetri Mega Probiotic

VetriScience Laboratories

This probiotic is unflavored, has eight different types of probiotic bacteria, and one type of prebiotic. Cats are only recommended to get ½ capsule a day so they’ll receive five billion colony forming units. This product requires refrigeration to maintain the viability of the bacteria but this bottle of 120 capsules will last a cat 240 days. Pet owners will also appreciate that this product has the NASC Quality Seal.

Best for Constipation: Purina Pro Plan Veterinary Supplements FortiFlora for Cats

Purina Pro Plan Veterinary Diets FortiFlora Probiotic Cat Supplement

Fortiflora is a favorite probiotic among veterinarians and pet owners. It contains liver flavor which makes it a tasty powder to entice constipated cats that may not want to eat and comes in a pre-portioned packet for ease of administration. Purina has scientific research backing this specific type of probiotic and each packet your cat consumes delivers 100,000,000 of one type of bacteria to benefit the gut. 

This product also contains some vitamins and minerals but each packet is still only one gram of powder so owners like how easy it is to mix into wet food. It does not require refrigeration but some pets with food sensitivities or allergies may not be able to tolerate the liver flavor.

Best for Kidney Disease: Vetoquinol Azodyl Probiotic Supplement

Vetoquinol Azodyl Kidney Health Supplement for Dogs & Cats

Azodyl contains three different types of bacteria that have been shown to support kidney function. Many veterinarians recommend administering it to cats with kidney disease or kidney failure but it may take two or three months for it to reach maximum effectiveness. It is safe to use with other kidney support products as well as other types of probiotics if necessary. This product is unflavored, should be stored in the refrigerator, and has the NASC Quality Seal. Unlike other probiotics, it should be administered whole and not sprinkled on your cat’s food.

Best for Kittens: PetAg Bene-Bac Plus FOS & Probiotics Gel Supplement

PetAg Bene-Bac Plus Pet Gel

Kittens are very small so Bene-Bac Plus is an easy way to administer seven different types of beneficial bacteria to support their tiny guts. This gel has recommendations for all sizes of kittens so pet owners appreciate the simple instructions and easy to swallow gel. Bene-Bac Plus contains 20 million bacteria in each gram and contains one prebiotic. It is sweetened with sugar so kittens usually like it and can be stored at room temperature.

Best for Acute Diarrhea: Nutramax Proviable-KP Supplement Kit

Proviable-KP Probiotic Digestive Health Supplement Kit

This kit not only comes with our pick for the best overall probiotic, Proviable-DC, but also a syringe of Proviable-KP to help with diarrhea in cats. This syringe contains a paste that has seven types of probiotics and two prebiotics plus kaolin and pectin. Kaolin and pectin absorb excess moisture in the gut that causes diarrhea and they also work fairly quickly so results are usually seen in just a day or two.

Proviable-KP paste can be used for up to three days and then the Proviable-DC capsules that this kit also comes with can be continued until they run out. No refrigeration is needed and there are no natural flavors in the paste or the capsules. Any leftover paste can also be saved and kept on hand in case your cat develops diarrhea in the future.

Best Budget: NaturVet Digestive Enzymes Plus Pre and Probiotic

NaturVet – Digestive Enzymes

One type of probiotic can be found in this digestive enzyme powder product. Various sizes of this powder are available but the four ounce container will last a cat 114 days. The digestive enzymes in this product may help your cat absorb nutrients from its food and the added pre and probiotics help establish good bacteria in the gut. 

NaturVet’s Digestive Enzymes Plus Probiotics have the NASC Quality Seal so you can rest assured that the product has what the label says it contains. 100 million colony forming units (CFU’s) of the probiotic and one type of prebiotic will be delivered to your cat with every ¼ teaspoon of powder that it consumes. Refrigeration is not necessary.

Final Verdict

There are a lot of probiotic options on the market but it’s important to know which ones contain viable bacteria and proof that they are beneficial to a cat. This makes Nutramax Proviable-DC (view at Amazon) our top pick since it is backed by science and is proven by third-party analyses to contain the viable bacteria that the package claims it has. It also does not require refrigeration, can be pilled or sprinkled on the food, and has no flavoring or additives that may cause problems for allergic or sensitive cats.

What to Look for in Probiotics for Cats

Delivery Method

Probiotics for cats most commonly come in a powdered form. Some products are packaged in sachets or packets designed to be opened and sprinkled on top of your cat’s food or mixed with water to syringe into your cat’s mouth while others are in digestible capsules. Capsules can typically be pilled as is, opened to sprinkle the contents onto the food, or opened to have the contents mixed into water to syringe into your cat’s mouth. 

Species-Specific Research

The best products will have proof of effectiveness through research that was done on cats. Not all animals need the same types of beneficial bacteria, so probiotics specifically shown to benefit cats are ideal.

Label Claims

Veterinary supplements, such as probiotics, are not regulated the same way pharmaceuticals are regulated. This means that the amount of probiotics that the product label says are present aren’t always accurate. Analyses from organizations such as and published studies verifying or denying these label claims have shown that not all probiotics have what they say they have in them. The National Animal Supplement Council (NASC) seal on product packaging is one way to tell if a product is likely to meet label claims, otherwise ask the company that makes the product if and how they ensure label claims are met.


Probiotics that also contain prebiotics are called synbiotics and these are the most effective types of products. Gum arabic, fructooligosaccharides (FOS), or other prebiotics should be listed on the product label.

Age of Cat

Smaller or younger cats may have a hard time consuming large amounts of a probiotic so the quantity of product needed to deliver a beneficial amount of the probiotics may matter. Elderly cats that don’t eat much may also do better with a product where you don’t have to give a lot of powder or paste.

Health Conditions

Certain types of probiotics have been studied to support specific bodily systems. Your cat may benefit more from one probiotic than another depending on what type of health condition it has and what kind of bacteria are in the product you choose.

Why Trust The Spruce?

Adrienne Kruzer is a Registered and Licensed Veterinary Technician in three states and has been writing about pet and vet information for over a decade. She also regularly lectures on pet supplements to fellow veterinary professionals and is employed by a major veterinary supplement manufacturer so supplements are her life! Her own pets regularly take supplements, including probiotics, because she fully understands the importance of them.

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