The 6 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
Combines fiber, calming herbs, flavorful protein, and five strains of good bacteria.
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Cats love this duck flavored daily chew made in the United States by a woman-owned business.
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Twenty strains of healthy bacteria—the most of any supplements we researched.
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Twelve strains of bacteria and prebiotic fiber support a healthy gut.
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Formulated by a naturopath to optimize overall kidney function.
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Concentration designed for small animals in easy to use syringe with seven strains of healthy bacteria plus probiotic.
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Have you heard about the many health benefits of taking probiotic supplements? Those benefits aren’t limited to humans. They’re also great for promoting your cat’s optimum health too. Probiotics are healthy gut bacteria and their dormant spores that help the good gut bacteria get and stay established, helping your cat thrive.

Although all cats will benefit from probiotics, they are particularly important for rescued animals, including pregnant and feral mothers and their kittens, because street cats are more likely to have been exposed to disease-causing bacteria. Probiotics come in a variety of forms including powders in sachets or packets, capsules and chewable tablets, pastes, and purées. Look for those that include multiple strains of bacteria. The best ones have live cultures and may need to be refrigerated. Choose a product that you’re sure you can dispense easily each day and be sure to check reviews for products that cats will actually eat. Consider those that also include prebiotics that promote the growth and survival of probiotics.

“Look for a probiotic that says it is designed for cats. Some probiotics are designed for both dogs and cats, while there are some just for cats. Both should work,” says Dr. Debra Eldredge, DVM and co-author of the Cat Owner's Home Veterinary Handbook. “Ideally you want a probiotic made in the U.S.A. and if it has the NASC [National Animal Supplement Council] seal of approval, even better.”

If your cat is struggling with digestive or other health issues, it's always important to consult with your veterinarian, who may be able to help guide your choice of probiotics. As with any supplement, you may need to try more than one type to find the right fit for you and your kitty.

Below are some of the best probiotics for cats readily available today.

Best Overall: Dr. Bill's Pet Nutrition Feline Digestive Support

Dr. Bill's Pet Nutrition Feline Digestive Support

Delivery Method: Powder | Life Stage: All | NASC Seal: Yes

What We Like
  • Includes digestive enzymes

  • Cats like the flavorful protein sources

  • Five strains of live healthy gut bacteria

What We Don't Like
  • Colony forming units (CFU) not listed on packaging

  • Some cats may be sensitive to one or more of the multiple protein sources

To earn the Best Overall spot on this list, a supplement needs to carry the NASC seal, be easy to dispense, and cats must want to take it. Dr. Bill’s Feline Digestive Support meets all of these criteria and more. Developed by veterinarian Dr. William Barnett, this powdered supplement contains five strains of good bacteria and eight common digestive enzymes to help break down the nutrients and minerals in a cat’s diet.

It contains ginger root, lemon balm, Psyllium husk, and the common plant sugar prebiotic fructoligosaccharides (FOS). Lemon balm and ginger root have been used for centuries as natural herbal remedies. Psyllium husk is a common dietary fiber component that absorbs liquid to form a gel that helps keep cats regular, and can help with hairballs in longhair cats.

Made in the United States, cats eat this supplement readily because it contains beef, chicken and whey protein isolates, and chicken liver. Beware that some online stores are selling this supplement for more than double the manufacturer’s price.

Best Budget: Pet Naturals of Vermont Daily Probiotic for Cats

Pet Naturals of Vermont Daily Probiotic for Cats

Delivery Method: Chew | Life Stage: All | NASC Seal: Yes

What We Like
  • Cats will eat these duck flavored chews reliably

What We Don't Like
  • Only one strain of healthy gut bacteria

  • Contains preservatives

Sometimes cats will turn their nose up when powders are added to their food. That’s where a daily treat will come in handy to help them get their daily dose of probiotic. Pet Naturals of Vermont Probiotic is a great daily treat.

Around $6 for a 30-day supply, cost won’t have to be the reason your cat is missing out on the benefits of daily pro- and prebiotics. This chew contains 100 million colony forming units (CFU) of a single strain of gut bacteria, the proprietary Ganeden BC30 Bacillis coagulans. This strain forms spores that are capable of surviving excessive stomach acids so that they can aid in active, healthy digestion in the intestinal tract.

These duck-flavored chews also contain the fiberm prebiotics, and arabic gum as well as healing aloe vera gel. A bonus is that they are said to improve bad breath. You can keep these shelf-stable treats on hand in a cool, dry place for any time your cat needs an extra digestive boost or doesn’t get a full dose using another method.

Pet Naturals of Vermont is a woman-owned business and the treats have the NASC seal so you can feel good about your purchase.

Best for Constipation: PetUltimates Probiotics for Cats

PetUltimates Probiotics for Cats

Delivery Method: Powder | Life Stage: All | NASC Seal: Yes

What We Like
  • Twenty strains of live healthy gut bacteria

  • No unnecessary ingredients that could cause sensitivity

  • 90-day money-back guarantee

What We Don't Like
  • No prebiotic

Constipation can be caused by a number of conditions. If this is an issue for your cat it's important to consult with your vet, and you might consider adding Pet Ultimates Probiotics for Cats to your pet's diet.

Each scoop of this no-nonsense supplement contains 5 billion CFU of 20 strains of live healthy gut bacteria plus a source of fiber—beta glucan—and alpha-galactocidase, a digestive enzyme that breaks down natural sugars so that they are easier to digest. That’s it.

Manufactured in the U.S. in a Food and Drug Administration registered Good Manufacturing Practices (GMP)-compliant facility, this supplement claims to reduce litter box odors and help your cat make firmer stools.

Best for IBD: Fera Pet Organics USDA Organic Probiotics with Prebiotics

Fera Pet Organics USDA Organic Probiotics with Prebiotics

Delivery Method: Powder | Life Stage: Adults of all breeds | NASC Seal: Yes

What We Like
  • Vegan, grain-free and without added colors, dyes, or preservatives

  • USDA Certified organic

  • Twelve live strains of gut bacteria

What We Don't Like
  • Some cats won’t eat it

Inflammatory bowel disease (IBD) is a syndrome in cats, a label applied to a collection of symptoms. It can present in your cat as diarrhea or constipation and is most commonly diagnosed in middle-aged to older cats, usually five to 12 years of age. The 12 live powerful strains of living good bacteria in Fera Pet Organic Probiotics with Prebiotics may help manage IBD.

With 5 billion CFU per scoop, your cat won’t notice when you stir this flavorless powder in with their food. Fera Pet’s formula has been certified organic by the U.S. Department of Agriculture (USDA) including the plant-based ingredients gum arabic and inulin that provide the bulk of the prebiotic fiber that will help keep your cat stay regular. FOS also works as a prebiotic to feed good gut bacteria.

This recipe was custom formulated by co-founding veterinarian Dr. Michelle Dulake and manufactured in the U.S. in FDA-registered GMP-compliant facilities and carries the NASC seal. Store in a cool, dry place for the best shelf-life.

Best for Kidney Disease: Healthy Kidney Inc. Kidney Restore For Cats & Dogs

Healthy Kidney Inc. Kidney Restore For Cats & Dogs

Delivery Method: Powder | Life Stage: Adult | NASC Seal: No

What We Like
  • Seven strains of gut bacteria

  • Balances five different factors related to kidney health

  • Money back guarantee

What We Don't Like
  • Some cats won’t eat it

Kidney disease in cats can sneak up on pet parents. Cats are often quiet about their symptoms so we don’t often realize they’re struggling until kidney problems have advanced. It is most common in older cats, especially those over ten years old, and you should consult with your vet about the best course of treatment.

Healthy Kidney’s Kidney Restore was formulated by naturopath Robert Galarowicz. Their recipe focuses on balancing five critical aspects of kidney health to reduce renal stress. The formula claims to balance phosphorus, potassium, acid build up, and supports elimination of toxins. One scoop contains 50 billion CFU of seven strains of good bacteria. FOS and camu camu powder are included as prebiotics. It also contains sodium bicarbonate that neutralizes acids, niacinamide (vitamin B3) to lower harmful phosphorus levels, and vitamin C as an antioxidant. 

Organic, GMO-free, and manufactured and tested in an FDA registered GMP-compliant facility in the Unites States, it’s easy for your pets to take mixed in with food. Some cat owners report that their cat wouldn’t eat it, but many others saw noticeable improvements in their cat within a couple of weeks or less.

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

PetAg Bene-Bac Plus Pet Gel

Delivery Method: Gel in syringe | Life Stage: All ages, including newborns | NASC Seal: No

What We Like
  • Syringe delivery method for quick, consistent dose

  • Seven strains of live bacteria

  • Suitable for newborns

What We Don't
  • Contains artificial color

Kittens are generally born without gut bacteria. They develop a healthy gut from the bacteria they receive while nursing and while exploring their environment. But kittens separated from their mother too early, those fed poor diets, and those experiencing trauma may struggle to establish a healthy gut community.  

PetAg Bene-Bac Plus Gel Digestive Supplement is an excellent solution because this combination pro- and prebiotic comes in a syringe for easy measuring and dispensing. Each dose can be given by weight with each gram containing 20 million CFU of seven strains of live healthy gut bacteria. PetAg also recommends this probiotic gel for traveling, post birth, after worming, at weaning, while boarding, post surgery, when dietary changes occur, post-antibiotic therapy and as indicated by your pet's veterinarian.

Kittens will love the sweet flavor of the FOS prebiotic and sunflower oil in each dose. The syringe helps with precise measurement and can be stored at room temperature.

Final Verdict

We like the Best Overall Dr. Bill’s Feline Digestive Support (view at Amazon) that combines prebiotic fiber, digestive enzymes, calming herbs, flavorful protein, and five strains of good bacteria. Cats don’t notice it in their food. Keep a bag of shelf-stable Pet Naturals of Vermont Cat Probiotic chews (view at Chewy) around for when your cat needs an extra boost or misses their daily dose for any reason.

What to Look for in Probiotics for Cats

Number and Diversity of Probiotics

Bacterial probiotics are most effective if they are living, not dead, and the more bacteria that are present, the higher the likelihood that they will benefit your cat. This means you want to choose a product that has a high number of colony forming units (CFU’s) or bacteria. Since you don’t know exactly what kind of bacteria your cat needs, you’ll also want to look for a probiotic that is a multi-strain product. This means there will be more than one type of bacteria in the product.


Since bacterial probiotics should be viable when you give them to your cat, you need to make sure they are properly stored to preserve them. Some probiotics require refrigeration, others need to stay below 77 degrees, and a few may not have any temperature requirements. Be sure to look for and follow the storage recommendations on the package.


If your cat has food sensitivities or allergies, check to see if the probiotic contains ingredients your cat cannot tolerate. Some products contain animal proteins, animal digest, grains, and other ingredients that could cause a problem in your cat or are simply a flavor that your cat does not like. Some will add ingredients like chicken to ensure your pet will want to eat them. If you have a picky eater or a cat that doesn’t respond well to capsules, consider using treats to ensure they are getting a quality dose of probiotics.

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 you can 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. If your cat has a health condition, it's always best to talk to your veterinarian before introducing a probiotic to your cat's treatment plan.


Do cats need a prescription for probiotics?

“Most probiotics are sold as supplements, so no prescription is needed. However, a few do require a prescription,” explains Dr. Eldredge. “That said, quality can vary greatly between products. Your veterinarian can guide you to the more reliable sources. You should always check before adding any supplement to make sure it will not interfere with your cat’s normal diet.”

Do probiotics have side-effects?

“Rarely, probiotics can cause mild stomach upset or extra gas,” notes Dr. Eldredge. “Sometimes this is a response to inactive ingredients in a particular product. In general, probiotics are very safe.” If your cat seems to exhibit side effects, discontinue the probiotic to see if the symptoms subside. You may need to try more than one product before finding the one that is a good fit for your cat.

Can cats take probiotics made for humans?

“No, cats should take probiotics made for cats,” says Dr. Eldredge. “The intestinal flora varies with each species, so bacteria that are ideal for people may not help cats at all (may not hurt but may not help). Some people eat live culture yogurt to get healthy bacteria, but many cats don’t handle dairy products very well. You could make things worse.” Stick to probiotics formulated specifically for cats.

Why Trust The Spruce Pets?

This piece was written by Lorraine Wilde who has had at least two cat companions in her home for the past 35 years, including some special needs kitties. When researching these brands, Lorraine evaluated the type and quality of the ingredients, the company’s research and development of the supplement, and their business ethics.

Her current senior feline companions have been challenged by digestive and urinary tract health issues. Because she has only the highest of standards for what she gives her pets, Lorraine recently started using Fera Pet Organic Probiotics, Kidney Restore and Pet Naturals of Vermont Probiotic chews to help improve her older cat’s digestive and urinary issues and to establish a healthy baseline for her dogs.

Lorraine holds a Bachelor’s degree in Biology and a Master’s degree in Environmental Science. She is a firm believer that consumers can make healthy and informed choices to protect their pets.

Dr. Debra M. Eldredge, DVM, graduated from Cornell University, where she was the first recipient of the Gentle Doctor Award, a prize given by the clinical faculty for the best patient care. She is an award-winning author and coauthor of more than 20 books on pets, including the Dog Owner's Home Veterinary Handbook and the Cat Owner’s Home Veterinary Handbook. Dr. Eldredge also writes for

We also consulted Spruce Pets contributor and Licensed Veterinary Technician Adrienne Kruzer, an expert in pet supplements, about what to look for in cat probiotics.

Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Wernimont SM, Radosevich J, Jackson MI, et al. “The Effects of Nutrition on the Gastrointestinal Microbiome of Cats and Dogs: Impact on Health and Disease.” Frontiers in Microbiology. doi:10.3389/fmicb.2020.01266

  2. Weber, Mickaël, et al. “Influence of the dietary fibre levels on faecal hair excretion after 14 days in short and long‐haired domestic cats.” Veterinary Medicine and Science. DOI:10.1002/vms3.6

  3. Edalat-Nejad, M et al. “The effect of niacin on serum phosphorus levels in dialysis patients.” Indian journal of nephrology vol. 22,3. DOI:10.4103/0971-4065.98751

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