Apple Cider Vinegar for Cats: Is It Safe, and Does It Work?

Apple cider vinegar (ACV) is a popular home remedy for people, and you'll find plenty of claims online that it can treat urinary tract infections, ear infections, fleas and ringworm in pets. So should you give apple cider vinegar to cats, and is it safe? Here's what veterinary sources actually say.

Our quick take: apple cider vinegar isn't poisonous to cats, but it has no proven health benefits for them and it isn't a treatment for any illness. It is acidic, cats dislike its taste and smell, and swallowing it can cause drooling, vomiting, diarrhea or loss of appetite, while putting it on the skin can cause irritation. It does not kill fleas, should never be put in a cat's ears, and won't cure a urinary infection, bladder stones or ringworm; trying to acidify urine at home can even make some bladder stones more likely. Cats are obligate carnivores and get what they need from a complete cat food, so there's no reason to add ACV to food or water. If your cat has signs of infection, a skin problem or urinary trouble, see your vet, and treat a cat straining to pee with little or no urine as an emergency.

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How safe is it to use with cats? … (1 minute read)

Are there any particular health benefits? … (1 minute read)

Internal applications of vinegar … (2.5 minutes read)

External applications of vinegar … (2 minutes read)

The side effects … (2 minutes read)

Apple Cider Vinegar For Cats: Is it safe?

Short answer: it isn't poisonous, but vets don't recommend it.

A veterinarian writing for PetMD notes that ACV is not toxic, but swallowing it can cause stomach and intestinal upset such as vomiting, diarrhea, drooling and loss of appetite. Cats also hate the taste and smell, and forcing liquid into the mouth of a struggling cat risks her inhaling it, which can lead to pneumonia. Before sharing anything from your kitchen, check our list of human foods cats can and can't eat.

Benefits Of Apple Cider Vinegar For Cats

So what's in it for kitty?

Some people think giving their cat apple cider vinegar will increase her potassium intake. The amount of potassium in apple cider vinegar is trace, and a complete and balanced cat food already supplies what a healthy cat needs. Cats with low potassium (common with kidney disease) need a supplement prescribed by a vet.

There is no good evidence that adding apple cider vinegar to a cat's food or water helps digestion, immunity, the coat or anything else. It can also put a cat off her food and water, which matters because many cats already drink too little.

It should be noted that undiluted apple cider vinegar can hurt your cat's esophagus.

Undiluted vinegar is the most irritating, but even diluted vinegar can upset a cat's stomach.

Internal Apple Cider Vinegar Use For Cats

As apple cider vinegar is highly acidic, it can irritate the lining of your cat's mouth, throat and stomach. This can cause drooling, vomiting, diarrhea or a cat who suddenly won't eat.

Even though the potency of apple cider vinegar is greatly diminished when blended with water, the issues that should be concerning to a pet owner still apply. Always talk with your vet before making any change to your cat's diet.

Respiratory Infections

Some websites claim apple cider vinegar eases breathing or clears respiratory infections. There is no evidence that it helps cats with respiratory infections.

Most cat “colds” are caused by feline herpesvirus or calicivirus. Mild cases often need only supportive care (keeping the nose clean, steam, tempting food), but your vet may prescribe antibiotics for secondary bacterial infections or antiviral eye medicine. See a vet promptly if your cat breathes with her mouth open, struggles to breathe, has thick green or yellow discharge, or stops eating, and keep her vaccinations up to date to reduce the risk.

Urinary Tract Infection (UTI)

Some websites recommend organic apple cider vinegar to treat urinary tract infections, also known as UTI. There is no evidence that it works in cats, and it is not a substitute for veterinary treatment.

True bacterial UTIs are less common in cats than many owners think, especially in young and middle-aged cats. Urinary signs such as straining, frequent trips to the litter box, peeing outside the box or blood in the urine are more often caused by feline idiopathic cystitis (bladder inflammation often linked to stress) or by crystals and bladder stones. Your vet needs a urine test to tell these apart, and a real infection needs the right antibiotic. A cat, especially a male, who strains but passes little or no urine may have a blocked urethra, which is an emergency. You can read more about urinary disease in our guide to common cat diseases.

Bladder Stones

You may read that apple cider vinegar acidifies urine and so breaks up the crystals that sometimes form in the bladder. Don't try this at home. Cats get two main types of bladder stones in roughly equal numbers: struvite and calcium oxalate. Some struvite stones can be dissolved with a prescription urinary diet that your vet formulates for the job and monitors with urine tests and X-rays. Calcium oxalate stones cannot be dissolved by diet and usually have to be removed, and making urine too acidic actually raises the risk of calcium oxalate stones.

Adding vinegar to your cat's food gives an uncontrolled dose of acid, can upset her stomach and may put her off eating. What does help urinary health is more moisture: feeding more wet cat food, offering fresh water in several places (a fountain helps some cats), keeping litter boxes clean and reducing stress.

Bladder stones and urethral plugs can block the flow of urine, so any cat with urinary signs should see a vet.

Follow your vet's treatment plan and go back for the recommended urine tests and X-rays to make sure the stones are gone.

External Apple Cider Vinegar Use For Cats

Putting apple cider vinegar on a cat's skin or coat isn't recommended either. It can irritate the skin, especially skin that is already scratched or inflamed. And cats groom themselves, so anything you put on a cat eventually ends up inside the cat.

Flea Treatment

Using apple cider vinegar to treat fleas is a popular idea, but it doesn't work. According to a veterinarian writing for PetMD, apple cider vinegar doesn't kill fleas. Any repellent effect is probably just the smell, and the risk of skin irritation outweighs the benefit. Use a vet-recommended flea treatment made for cats, treat every pet in the home, and never use a dog flea product on a cat: some contain permethrin, which can cause fatal poisoning in cats.

Is it Safe if She Ingests it?

Licking a little diluted vinegar off her coat is unlikely to poison your cat, but it can cause drooling and stomach upset. Keep vinegar well away from her eyes and nose.

Ear Infections

Never put apple cider vinegar, or rubbing alcohol, in a cat's ears. Both sting an inflamed ear canal, can dry and irritate the skin, and may make an existing infection worse or cause damage if the eardrum is torn. Ear trouble in cats is often caused by ear mites, allergies or polyps, which need a proper diagnosis and the right medication.

See your vet if your cat shakes her head or scratches her ears, or if you notice dark or smelly discharge, redness, a head tilt or loss of balance. For routine care, follow our guide on how to clean cat ears safely with a vet-approved ear cleaner.

Never push cotton swabs into the ear canal: they can pack debris deeper and injure the ear.

Ringworm and Itchy Skin

There is no evidence that apple cider vinegar cures ringworm or other skin conditions, and acid on broken or inflamed skin stings and can make it worse. Ringworm is a contagious fungal infection that can also spread to people. According to VCA Animal Hospitals, treatment usually lasts at least six weeks and combines vet-prescribed antifungal medicine with thorough cleaning of the home.

For itchy or dry skin, see your vet. Common causes include fleas, food allergies and environmental allergies, and each needs a different treatment.

The Side Effects of ACV for Cats

Swallowing apple cider vinegar can cause side effects, especially if your cat already has a health problem. The acid can irritate the mouth, throat and stomach, and cats often drool, vomit or refuse food afterward.

Stomach Problems

Using apple cider vinegar for the purpose of treating existing stomach problems can only worsen the situation. Do not attempt to give apple cider vinegar to a cat with digestive issues such as ulcers, vomiting and the like.

The acidity of apple cider vinegar won't settle an upset stomach and is more likely to make it worse. Vomiting that keeps happening or lasts more than a day needs a vet.

Diarrhea

Apple cider vinegar can cause diarrhea. It is not a treatment for constipation in cats. Ask your vet about safe options, such as adding moisture to the diet or a fiber supplement, and see a vet if your cat strains without passing stool for more than a day or two.

For kittens and senior cats, diarrhea can quickly lead to dehydration. They have smaller reserves than healthy adults, so they can become weak and lethargic faster.

Orally feeding this substance to your cat in order to treat an illness is not a good idea as you may not know what is wrong with your cat and how she will react to apple cider vinegar.

Kidney Disease

Don't give apple cider vinegar to cats with kidney disease. Chronic kidney disease already upsets the body's acid-base balance, and many of these cats struggle with nausea, poor appetite and stomach irritation, so extra acid is the last thing they need.

Are There Any Nutrition Benefits?

While apple cider vinegar has some health benefits for humans, it has none at all for cats. The potassium and magnesium found in apple cider vinegar are just far too low to be of use.

Your pet would have to drink gallons of vinegar before any of these minerals would have an effect on her system.

And what's more, the acid would upset her stomach long before she got anything nutritious from the vinegar.

To put it very simply, adding this to your cat’s diet for nutritional purposes is not a wise decision. And there's no other proven health benefit for cats either.

Takeaway

Apple cider vinegar has a reputation as a cure-all, but for cats the evidence just isn't there.

There is no nutritional value in feeding your cat apple cider vinegar, and it does not treat respiratory infections, urinary tract infections or bladder stones. Trying to acidify your cat's urine at home can even raise the risk of calcium oxalate stones.

On the outside, it doesn't kill fleas, it should never go in a cat's ears, and it isn't a treatment for ringworm or other skin infections. It can upset the stomach and should be avoided completely in kittens and in cats with kidney disease, digestive problems or urinary issues.

If your cat has any of these problems, a vet visit is the quickest and safest way to find and treat the real cause. Curious which other kitchen ingredients are safe? See our guide to nuts, herbs and spices for cats.

Sources

• PetMD (Barri J. Morrison, DVM), “Can Pets Have Apple Cider Vinegar?” (2024)
• PetMD: apple cider vinegar for fleas
• PetMD (Jennifer Coates, DVM), “The Effects of Diet on Bladder Stones in Cats”
• VCA Animal Hospitals: urinary tract infections in cats; ringworm in cats