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. Debra Eldredge, DVM and co-author of the Cat Owner's Home Veterinary Handbook . “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.

The 6 Best Probiotics for Cats of 2023

Reviewed & Approved

Our top pick is Dr. Bill’s Pet Nutrition Feline Digestive Support, which has five strains of healthy, live bacteria and digestive enzymes. If you’re looking for a supplement that’s safe to give to kittens, check out PetAg Bene-Bac Plus FOS & Probiotics Gel Supplement.

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. “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. We researched, and consulted with a veterinarian, the best probiotics for cats based on their delivery method, NASC approval, and number of active cultures.

Here are the best probiotics for cats.

Our Top Picks

Best Overall:

Dr. Bill's Pet Nutrition Feline Digestive Support at Amazon

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Best Budget:

Pet Naturals of Vermont Daily Probiotic for Cats at Amazon

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Best for Constipation:

PetUltimates Probiotics for Cats at Amazon

Jump to Review

Best for IBD:

Fera Pet Organics Probiotics with Prebiotics at Amazon

Jump to Review

Best for Kidney Disease:

Healthy Kidney Inc. Kidney Restore at Amazon

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Best for Kittens:

PetAg Bene-Bac Plus FOS & Probiotics Gel Supplement at Amazon

Jump to Review

Best Probiotic Deodorizer:

Skout's Honor Skout's Honor Probiotic Deodorizer at Amazon

Jump to Review

In This Article

Our Picks
What to Look for
FAQ
Why Trust The Spruce Pets

4.7

Dr. Bill's Pet Nutrition Feline Digestive Support

Amazon

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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

Our top pick, Dr. Bill’s Feline Digestive Support, carries the NASC seal, is easy to dispense, and is flavored so you cats enjoy taking it. 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.

This supplement 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.

It also contains beef, chicken and whey protein isolates, and chicken liver, so your cats will happily take it with their food. Be sure to check with your veterinarian before incorporating this supplement into your cat's diet as some cats may be sensitive to some of the protein sources in this formula. Note that some online stores are selling this supplement for more than double the manufacturer’s price.

_{Delivery Method: Powder | Life Stage: All | NASC Seal: Yes}

Pet Naturals of Vermont Daily Probiotic for Cats

Amazon

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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.

_{Delivery Method: Chew | Life Stage: All | NASC Seal: Yes}

Amazon

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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.

_{Delivery Method: Powder | Life Stage: All | NASC Seal: Yes}

The 7 Best Cat Supplements of 2023

Fera Pet Organics USDA Organic Probiotics with Prebiotics

Amazon

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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.

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

Healthy Kidney Inc. Kidney Restore For Cats & Dogs

Amazon

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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.

_{Delivery Method: Powder | Life Stage: Adult | NASC Seal: No}

The 6 Best Frozen and Freeze-Dried Raw Cat Food of 2023

Amazon

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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.

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

The 6 Best Canned Cat Foods of 2023

Skout's Honor

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What We Like

Variety of scents, including a hypoallergenic unscented version
Safe enough for daily use
Can be used on both cats and dogs

What We Don't Like

Unclear if probiotics have any benefit in this context
Only available in one size

Your cat's personal microbiome isn't just in their stomach—they (and we) also have a living ecosystem on the surface of our skin! Skout's Honor Probiotic Deodorizer includes topical probiotics that are meant to encourage a healthy microbiome, crowding out bacteria that cause bad smells, dryness, and itching. While recent studies into topical probiotics have promising results—providing potential treatments for acne and psoriasis in humans, for example—the research isn't advanced enough to say for sure if probiotics really are effective deodorants.

But even absent specific probiotic claims, Skout's Honor Deodorizer makes a good case for itself, by providing a hydrating and smell-reducing spray that can be used as needed. It includes natural ingredients like avocado oil to keep skin protected.

In addition to its hypoallergenic unscented version, Skout's Honor Probiotic Deodorizer is available in four different scents: Sandalwood Vanilla, Honeysuckle, Lilac & Linen, and Lavender.

_{Delivery Method: Spritzing spray | Life Stage: All ages | NASC Seal: No}

Final Verdict

We like the Best Overall Dr. Bill’s Feline Digestive Support 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 around for when your cat needs an extra boost or misses their daily dose for any reason.

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.

Storage

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.

Flavor

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 ConsumerLab.com 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.

Prebiotics

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.

FAQ

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. Debra Eldredge, DVM and co-author of the Cat Owner's Home Veterinary Handbook. “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.

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, Wilde 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, Wilde 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.

Wilde 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 SeniorTailWaggers.com.

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.