Why Is My Cat Foaming At The Mouth? 6 Causes Of Hypersalivation

Is your cat foaming at the mouth? Don't panic—there may be an easy remedy. Regardless, you should bring your pet to the vet to get checked over, as foaming at the mouth could indicate an underlying health issue.

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Last Updated: December 13, 2023 | 7 min read

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On the last trip to the vet, I noticed my cat, Lucy, had begun to foam at the mouth. I was immediately concerned. I had never seen this reaction. Did she get into something when I wasn’t looking? As it turns out, some cats foam at the mouth when experiencing fear and anxiety.

I learned that hypersalivation is the technical term for the combination of heavy panting and excessive, frothy drool I saw in my pet. While stress is one cause of a foamy mouth, many other potential causes exist, such as ingestion of toxins, viral infections, and dental disease.

To prevent health-related foaming at the mouth, work to cat-proof your home and maintain a safe, comfortable space for your feline companion. Depending on the diagnosis, your veterinarian may recommend a treatment plan for recovery.

Why Is My Cat Foaming At The Mouth?

What is your first thought when you hear about an animal foaming at the mouth? Chances are that your mind goes to rabies. Foaming at the mouth is one of the most notable symptoms of rabies, a deadly virus affecting mammals’ central nervous system.

While we often associate rabies with wild animals—bats, raccoons, skunks, and foxes are common carriers—domestic animals like felines can also become infected. According to the Centers for Disease Control and Prevention (CDC), more than 250 cats are reported rabid each year. While rabies could be a potential reason of foaming at the mouth, many other more likely causes exist. So, don’t panic if you see your kitty foaming at the mouth. The best thing you can do is contact your veterinarian for support.

6 Common Causes Of Hypersalivation In Cats

Is your cat suddenly foaming at the mouth? The medical term for excessive drooling is hypersalivation. Hypersalivation can occur for various reasons, ranging from minor concerns to severe medical issues.

1. Nausea

Your pet may froth at the mouth if they’re experiencing nausea. A range of medical issues may cause nausea. The most common are:

  • Constipation
  • Diabetes
  • Eating human foods that can cause an upset stomach
  • Food allergies
  • Hairballs
  • Hyperthyroidism
  • Inflammatory bowel disease (IBD)
  • Intestinal parasites
  • Kidney disease
  • Liver disease
  • Motion sickness
  • Switching to a new food or treat
  • Toxin ingestion
  • Viral infections

Pay attention to other behaviors—along with hypersalivation—that could signal that your cat is nauseous:

  • Hiding
  • Increased vocalization
  • Lethargy
  • Licking or smacking lips
  • Not eating
  • Retching without vomiting

It is imperative to bring your cat to the vet if they show any of these problems that are not quickly resolved. If your cat hasn’t eaten for 24 hours, has severe lethargy, or starts vomiting, bring your cat to an emergency clinic as soon as possible. If your feline shows signs of nausea but only displays mild symptoms, scheduling a visit with your regular veterinarian for an examination is acceptable.

2. Anxiety & Stress

As with driving my kitty to the vet, a stressed cat may open-mouth pant and drool when overwhelmed or anxious. Along with foaming at the mouth, the following signs indicate an acute stress response in cats. 

  • Aggression
  • Dilated pupils and flattened ears
  • Growling, hissing, yowling, and other vocalizations
  • Hiding
  • Immobility
  • Rapid breathing
  • Shaking

Triggers of anxiety vary but may include:

  • Baths
  • Confinement
  • Hospital visits
  • New socialization, such as a new pet or group housing
  • Travel

If acute stress is causing your feline to foam at the mouth, talk to your vet about prescription drugs for anxiety. Our article covering cat sedatives for travel shares both prescription and over-the-counter options for anxiety relief. You can also explore other options, including pheromones—Feliway, ThunderEase, bSerene—and herbal attractants, like catnip. Research shows that these types of olfactory stimuli effectively reduce cat stress. Just be sure to get your vet’s okay before using any of these products.

3. Medication Side Effects

Felines may foam at the mouth after taking a medication for several reasons. First, your cat may salivate excessively to eliminate a medication’s bitter or sour taste. Second, your cat may be allergic to the medication and show signs of an allergic reaction.

If your cat begins foaming at the mouth after starting on a new medication, contact your veterinarian. In the case of an allergic reaction, your vet may want to assess the severity of the reaction and offer a treatment plan and/or alternative medication.

4. Dental Problems

The Cornell Feline Health Center reveals that between 50 and 90 percent of felines older than four years of age experience some form of dental disease. Many dental diseases, such as stomatitis and gingivitis, cause hypersalivation. Symptoms will gradually worsen over time as the disease progresses.

The best way to protect your pet from dental-related drooling is to properly care for your feline’s oral hygiene to prevent issues. Brush your cat’s teeth daily using a quality toothbrush. Supplement their dental routine with dental treats.

5. Overheating

Felines can foam at the mouth during hyperactivity or overheating. Cats have limited sweat glands, so they use other methods to cool themselves. Felines will groom themselves, and when the excessive saliva evaporates, it cools the skin. They will also find a shady spot to rest during periods of high heat. Foaming at the mouth and panting is a sign of heat stroke in cats.

It could be a sign of distress if you notice your cat panting, drooling, and excessively grooming on a hot day. Give your cat cool water or place a bag of ice near your cat to bring their temperature down. If your cat continues to show signs of distress or heat exhaustion, take them to the vet immediately.

6. Poisoning

There is a chance that your cat has come in contact with a toxic substance if they are drooling and frothing at the mouth. Many household products are dangerous to cats, including disinfectants, detergents, salt lamps, medications, grapes, onions, and garlic.

Other signs of cat poisoning include:

  • Breathing difficulties (rapid or labored)
  • Coughing
  • Diarrhea
  • Fever
  • Lethargy
  • Loss of appetite
  • Shock or collapse
  • Skin inflammation, swelling
  • Twitching or seizures
  • Vomiting
  • Weakness

If you believe your cat has ingested a poison, seek medical help immediately.

Other Causes Of Foaming At The Mouth In Cats

While not as common, cats may also foam at the mouth due to the following:

  • Calicivirus (a virus causing upper respiratory tract infection)
  • Foreign body
  • Kidney disease
  • Liver disease
  • Neurological disorders
  • Rabies
  • Seizures
  • Soft tissue damage

When in doubt about the cause of your cat’s hypersalivation, the best step you can take is to seek veterinary assistance.

A Vet’s Expert Opinion

“I don’t commonly see cats foaming at the mouth in my clinic; it’s certainly not an everyday occurrence,” says veterinarian Rebecca MacMillan, BVetMed, BSAVA, PGCertSAM. “However, when I do see these cases, it is usually because they have licked or eaten an irritant. Bitter or toxic things can cause your cat to foam at the mouth or drool.”

In the case of a feline consuming an irritant, the vet will ask about your pet’s history and examine their mouth for abnormalities. They may also take blood samples or prescribe anti-nausea or anti-inflammatory medication. In extreme cases, your feline may be hospitalized during recovery.

Dr. MacMillan recommends visiting the vet when your feline is foaming at the mouth, even if this is their only symptom. “While many cats can drool a little bit from time to time (some owners report this if their cat is very relaxed, or perhaps when they are feeling nauseous, e.g., travel-sick), foaming at the mouth is likely to be a sign of a more significant underlying issue,” says MacMillan. “It’s better to be safe than sorry, so give your vet a call.”

Our Experience With Cats Foaming At The Mouth

I have a cat, Zaphod, who is a skilled escape artist. He is an indoor-only cat but loves to sneak outside and roll in the grass. I will occasionally take him outside for short, supervised grass-playing sessions or walks on a leash since he enjoys it so much. While he loves it, things can quickly get out of hand when he starts rolling around in the grass and eating it. When he eats too much grass, it greatly upsets his stomach. This is one of the few times I have seen him vomit up foam. When this happens, he usually will throw up the foam a couple of times and, with it, some large blades of grass.

Zaphod loves grass, as well as plants. I have a large collection of spider plants with leaves resembling large blades of grass. These are a true temptation for Zaphod, and he has managed to get ahold of a piece or two. Eating plants has been the other time I have seen him throw up foam like he does with grass. The plant material and the large bits he swallows cannot be digested. Because of this, plants are kept out of reach, and playing outside in the grass is a limited, supervised activity.

Danielle DeGroot, rescue cat parent and pet care expert

Frequently Asked Questions

Here are some frequently asked questions about cat hypersalivation. Don’t see yours? Ask us in the comments.

What Should I Do If My Cat Is Foaming At The Mouth?

The best step you can take when you notice that your cat is frothing at the mouth is to visit your vet. Your vet will examine your feline and determine the best course of action. For example, if your cat is diagnosed with a dental disease, your vet will recommend that your cat’s teeth be professionally cleaned. In the case of a toxin, your vet may induce vomiting and use IV fluids to prevent dehydration or correct their electrolyte status.

Why Is My Cat Foaming At The Mouth But Otherwise Acting Normal?

Your cat may be foaming at the mouth for any number of reasons. Maybe they just swallowed a foul-tasting bug. Continue monitoring your cat for other signs of distress. If you notice any additional behavioral changes, contact your vet right away.

Consider Pet Insurance

While you may not think pet insurance is worth the cost when your pet is healthy, investing in a quality health insurance plan can save you thousands of dollars in future vet bills. Feline pet insurance can help cover the cost of accidents and illnesses related to foaming at the mouth. Are you interested in picking out a plan? View our picks for the best pet insurance and best dental insurance for cats.

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