Why Is My Cat Drooling? Causes, When to Worry & What to Do

Is Cat Drooling Normal? The Quick Answer

Some cats drool when they’re happy — while purring, kneading, or being petted. That’s normal if it’s a small amount, only happens during relaxation, and stops when your cat becomes alert. But drooling in cats is relatively uncommon, so new, excessive, or persistent drooling should always be discussed with a vet. Cats hide pain extremely well, so “acting normal” doesn’t rule out a problem.

When to Worry: Normal vs Emergency

Happy Drool vs Sick Drool: A Quick Comparison

If your cat matches the right-hand column on even one or two signs, use the guidance below.

Normal drooling (no vet needed)

• Only during purring, kneading, being petted, or deep sleep
• Small amount that stops when your cat is alert
• Your cat eats, drinks, plays, and grooms normally
• Breath smells normal; no pawing at the mouth
• Pattern consistent over months or years (many happy-droolers start as kittens)
• Brief drooling after a bitter medication that resolves quickly

Call your vet (same or next day)

• Drooling is new, excessive, or has lasted more than 24 hours
• Drooling happens regardless of mood — not just during happy moments
• New bad breath, blood-tinged or foul-smelling saliva
• Eating less, dropping food, chewing on one side, or preferring soft food
• Pawing at the mouth or face, head shaking
• Vomiting, gagging, lip smacking, or repeated swallowing

Emergency — go to the vet NOW

• You suspect poisoning or plant exposure (especially lilies)
• Difficulty breathing, open-mouth breathing, or blue/pale gums
• Your cat can’t close its mouth or the jaw looks droopy
• Signs of heatstroke (heavy panting, weakness in a hot environment)
• String hanging from the mouth — do NOT pull it (why this matters is explained in the causes section below)
• Drooling with lethargy, weakness, hiding, or collapse

Drooling but Acting Normal — Should You Still Worry?

This is one of the most common questions vets hear, and the honest answer is: don’t let normal behaviour reassure you completely. Cats are masters at hiding pain — in the wild, showing weakness attracts predators, so your cat may eat, play, and purr while coping with significant mouth pain or early illness.

Use the comparison table above rather than your cat’s mood as your guide. Drooling that’s new, getting heavier, or paired with even subtle changes — slightly less interest in dry food, a head tilt while chewing, sleeping a bit more than usual — deserves a vet check within a day or two, even if your cat seems “fine”. The one exception is classic happy drooling: tiny amounts, only during relaxation, in a cat that’s done it for years. When in doubt, call your vet surgery and describe what you’re seeing — they’d much rather reassure you over the phone than treat an advanced problem later.

Why Is My Cat Drooling? All the Causes

Happy and content drooling

Some cats drool while purring, kneading, or being petted. Endorphins released during these activities stimulate the salivary glands — it’s thought to be a holdover from nursing behaviour. Most happy-droolers start doing it as kittens and continue for life. The key signs it’s benign: small amount, tied to relaxation, stops when alert, and your cat eats and behaves normally.

Stress or anxiety

Car rides and vet visits commonly trigger drooling, often with vocalising, flattened ears, and attempts to escape. Stress drooling should resolve once the stressor is gone. If it continues long after, suspect an underlying issue. (If the drooling happens specifically in the car, see motion sickness below — it’s a separate problem with its own fix.)

Motion sickness

Some cats drool, vocalise, or vomit during car journeys — not from fear alone but from genuine motion sickness, much like people get. Signs tend to start shortly after the car moves and ease once the journey ends. If your cat only drools in the car, talk to your vet about travel strategies: a covered carrier secured in a stable position, short practice trips to build tolerance, and in some cases anti-nausea medication prescribed for travel days.

Bitter taste

Bitter medications (especially liquid antibiotics like metronidazole), chewing a pill, licking topical flea treatment, or eating a bug can cause profuse drooling and even foaming. This is usually self-limited — rinse your cat’s mouth with cool water if they’ll allow it, and it should pass quickly.

Teething in kittens

Kittens lose their baby teeth and grow their adult set between about 3 and 6 months old, and sore gums during the swap can cause mild drooling — sometimes with tiny spots of blood on chew toys. Offer a kitten-safe chew and follow their progress with our kitten age chart. If drooling is heavy, smells bad, or your kitten goes off food, see your vet — that’s more than teething.

Dental disease — the #1 medical cause

Periodontal disease affects an estimated 85% of cats over the age of six. Tartar buildup leads to painful gum inflammation, loose teeth, and mouth ulcers. Warning signs include:

• New or worsening bad breath
• Blood-tinged saliva
• Dropping food or chewing on one side
• Preferring wet food over dry
• “Hungry but runs away from the bowl” — running to the dish, then vocalising or walking away

Definitive diagnosis usually requires sedation and dental X-rays, since disease hides below the gumline. (Cornell’s guide to feline dental disease)

Stomatitis and tooth resorption

Stomatitis (severe gum inflammation) affects roughly 1 in 100 cats and causes painful, foul-smelling drool. Tooth resorption — painful lesions where the tooth structure breaks down — can be extremely painful yet nearly invisible to owners, even after teeth have fallen out. (Cornell University on tooth resorption)

Something stuck in the mouth

String, toy parts, grass, or bones can lodge across the hard palate or wrap around the base of the tongue. Look for pawing at the mouth, gagging, or difficulty closing the mouth. Never pull string hanging from your cat’s mouth — it may be wrapped around something in the stomach or intestines, and pulling can cause catastrophic internal damage. Go to the vet immediately.

Oral tumours

Feline oral squamous cell carcinoma is the most common malignant mouth tumour in cats, accounting for three-quarters or more of all oral tumours. Early stages can look just like ordinary dental disease. Warning signs: excessive drooling, bad breath, blood in the food or water dish, difficulty eating, loose teeth, facial swelling, or a tongue that sticks out. Diagnosis requires a biopsy under anaesthesia.

Nausea

Drooling is the feline equivalent of “mouth watering” before vomiting. Causes include hairballs, diet changes, gastritis, motion sickness, or systemic illness. Clues: lip smacking, repeated swallowing, crouching, hiding, or reduced appetite. Most sudden drooling from nausea resolves within a couple of hours.

Poisons and toxic plants

If you suspect poisoning, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435 immediately — it’s open 24/7 (a consultation fee may apply). Don’t wait for symptoms to worsen.

Lilies are an emergency — treat any exposure plus symptoms as urgent. Other culprits include caustic cleaners, human medications, insecticides, and plants with needle-like oxalate crystals (dieffenbachia, philodendron, peace lily). For oxalate plants: remove any plant material from the mouth and encourage cool water (a little tuna liquid can entice drinking). Some sources suggest a small amount of milk or yogurt because calcium can help bind oxalate crystals — but treat this only as a stopgap while you arrange veterinary advice, never as a substitute for it. (FDA’s guide to pet poison emergencies)

Heatstroke

Cats don’t pant to cool down the way dogs do, so open-mouth breathing and drooling in a hot environment are serious warning signs. Heatstroke can develop in a parked car, a sunny conservatory, or an unventilated room — and it can turn fatal quickly. Move your cat somewhere cool immediately, offer small amounts of cool (not ice-cold) water, and get to a vet without delay. This is always an emergency.

Kidney and liver disease

In senior cats, kidney disease causes toxin buildup leading to painful mouth ulcers. Drooling is often one of the first symptoms of liver disease too. Annual blood work (twice yearly for seniors) catches these early.

Respiratory infections

Feline calicivirus causes painful mouth ulcers on the tongue, gums, and palate — leading to drooling and refusal to eat. Watch for sneezing, nasal discharge, fever, and lethargy alongside the drooling. If coughing is the main symptom rather than drooling, see our guide to coughing in cats.

What to Do Right Now: 6 Steps

1. Check for emergencies first. Toxin suspected? Breathing trouble? Can’t close mouth? String visible? Lethargic? If yes — emergency vet now, don’t wait.
2. Secure possible toxins. Remove any suspicious substance or plant from reach. Bring packaging or a photo to the vet.
3. Do a gentle mouth check. If your cat tolerates it, use a flashlight to look under the tongue and around the teeth for string, swelling, or ulcers. Don’t force the mouth open. Never pull string.
4. Offer easy food and water. Wet or softened food, fresh water in a shallow bowl. Note whether your cat eats dry vs wet — your vet will ask.
5. Note the context. When did it start? Only when relaxed, or constant? Any recent changes — new food, medications, plants chewed, vomiting, appetite changes?
6. Monitor, don’t medicate. Never give human medications or antibiotics without a vet’s prescription. Drooling lasting more than a few hours without an obvious cause warrants a vet visit.

If you’re also considering spaying or neutering your cat, our complete guide covers costs, timing, and recovery.

What to Expect at the Vet

Your vet will do a thorough physical exam including a careful mouth check. Depending on findings, expect: a sedated oral exam, dental X-rays, blood work (kidney/liver markers), and possibly ultrasound or CT if a tumour or foreign body is suspected. Treatment follows the cause — dental cleaning or extraction, decontamination and fluids for toxins, anti-nausea medication, or surgery for trauma.

Before your visit, gather: when the drooling started, whether it’s constant or situational, eating and drinking changes, other symptoms, any exposures (medications, plants, string), and your cat’s age and vaccination history.

How to Prevent Drooling Problems

Most serious drooling has a dental root, and dental disease is largely preventable. Brush your cat’s teeth daily with a feline tooth gel — even a few times a week is far better than nothing. Choose dental treats that carry a recognised seal of acceptance rather than relying on “dental” marketing claims, and schedule professional cleanings as your vet recommends; early professional cleaning gives your cat a fresh start that home care then maintains. (Cornell’s advice on feline dental care)

Frequently Asked Questions

Do cats drool when they’re happy?

Yes. Some cats drool while purring, kneading, or being petted. It’s normal if it’s a small amount, only during relaxation, and your cat is otherwise healthy.

Why is my cat drooling and not eating?

This is a classic oral-pain pattern — dental disease, a foreign object, mouth ulcers, or a tumour. It can also indicate nausea. See your vet promptly; cats that stop eating can develop liver problems within days.

Is it normal for cats to drool in their sleep?

An occasional small damp spot during deep sleep can be normal. Frequent, excessive, foul-smelling, or discoloured drool during sleep is not — get it checked.

My cat is drooling after medication — is this normal?

Yes, if the medication tastes bitter. Rinse your cat’s mouth with cool water if they’ll allow it, and try mixing the medication into a small portion of food next time. It should resolve within 10–15 minutes.

Why is my cat drooling thick saliva?

Thick, sticky, or foul-smelling saliva in an older cat can indicate kidney disease, stomatitis, or painful tooth resorption. This needs a vet visit — don’t wait.

Can I treat my cat’s drooling at home?

Only the obvious benign cases (brief drooling after a bitter taste, happy drooling). Persistent or unexplained drooling has no safe home treatment — it needs a proper diagnosis, which often requires sedation and X-rays.

Photo Credits

Happy relaxed cat with eyes closed — some cats drool when content — Flickr, CC BY-SA. Veterinarian examining a cat at a vet checkup — Flickr, CC BY-SA.