My cat is drooling: normal causes, warning signs and what to do
Unlike some dogs, cats do not usually drool, so when they do it is worth paying attention. There is good drool, from a happy cat kneading and purring on your lap, and warning drool that points to mouth pain, a toxin, a foreign body or nausea. This is how to tell them apart.
Normal drool: pure contentment
Some cats drool when they are deeply relaxed: lying on your lap, purring, kneading with their front paws and with half-closed eyes. It is a response many keep from kittenhood, when they suckled, and it signals no problem at all. Some cats also drool at the sight of very tempting food, or when they smell catnip. Context is the key: if the drool only appears at those moments, stops as soon as the cat gets up, and the cat eats, grooms and behaves normally, there is nothing to treat. A blanket on your lap and you are done. If a cat that never drooled starts doing so, or drools outside those situations, that is a different matter.
The most common cause of abnormal drool: the mouth
Anything painful in the mouth can cause drooling: advanced periodontal disease, teeth with resorptive lesions (very common and very painful in cats), a broken tooth, ulcers caused by calicivirus, gingivostomatitis or an oral tumour. These cats often have bad breath, chew on one side, drop food, go up to the bowl and walk away, or paw at their face. The saliva may be thick, contain bits of food or a little blood, and the fur on the chin and chest looks dirty because the cat stops grooming due to pain. In an older cat that drools, one of the first suspects is oral squamous cell carcinoma, which is best detected as early as possible.
Foreign bodies: the thread under the tongue
Cats play with threads, hair bands, ribbons, tinsel and fishing line, and their tongue has hook-shaped papillae that make it hard to spit out what goes in. A thread can get looped around the base of the tongue with the rest swallowed, and if the other end travels down the intestine, it can cut through it. A cat that drools, keeps trying to swallow, paws at its mouth and does not want to eat may have a trapped thread. If you see one hanging from its mouth or bottom, never pull it: you can cause serious internal injuries. Take it to the vet immediately. The same goes for chicken bones, fish bones or bits of toy wedged between the teeth or in the palate.
Toxins, bitter tastes and plants
Many toxins cause drooling: dog spot-ons containing permethrin applied to a cat by mistake (which also cause tremors and seizures), insecticides, cleaning products, liquid air freshener or potpourri, and some irritant plants such as dieffenbachia, pothos or poinsettia, which cause drooling and mouth discomfort. It is also very typical for a cat to drool dramatically, even foaming at the mouth, after tasting something bitter: a tablet, a spot-on it has licked or a liquid medicine. That foaming usually settles within minutes and is not serious in itself, but if you do not know what it has licked, treat it as possible poisoning and seek advice.
Nausea, stress and other causes
A nauseous cat drools, licks its lips and swallows before vomiting. Behind it may be any digestive problem, advanced kidney disease, pancreatitis or car sickness: it is very common for a cat to drool in its carrier during a journey from stress or motion sickness. Burns from caustic products or from biting an electric cable cause drooling with pain and wounds in the mouth. Some neurological diseases that affect swallowing, rabies (very unlikely in mainland Spain, but worth remembering in cats with a history of irregular importation) and heatstroke can also cause drooling. That is why sudden drooling with no clear explanation warrants a vet visit.
When it is an emergency
Go to the emergency vet if the drooling comes with tremors, seizures, dilated pupils, staggering or difficulty breathing; if you know or suspect it has touched a toxin, a dangerous plant, a dog spot-on or a cleaning product; if you see a thread coming from its mouth; if it is drooling a lot of blood or has bitten a cable. See the vet the same day if it suddenly drools for no apparent reason and is not eating, if it paws at its mouth a lot or seems subdued. Book an appointment within a few days if the drooling is mild but persistent, if it has bad breath or if you notice it eating oddly. A cat that stops eating for more than a day also needs a vet, because of the risk of hepatic lipidosis.
What the vet will do
A full examination of the mouth, which in a cat in pain can sometimes only be done properly under sedation: teeth, gums, the top and underside of the tongue, the palate and the throat. If a toxin is suspected, the vet will ask what products you have at home, and bringing the packaging or a photo of the label helps enormously. Blood tests may be needed to assess the kidneys and liver, X-rays if a foreign body is suspected, and dental X-rays if resorptions or broken teeth are suspected, which often cannot be seen with the naked eye. If there is a mass, a biopsy will be taken. Once there is a diagnosis, treatment ranges from a dental clean and extractions to decontamination for a toxin or surgery.
What it costs in Spain in 2026
As a guide: consultation, €40 to €60; out-of-hours emergency, €70 to €150 for the visit alone; sedation to examine the mouth, €40 to €100; blood tests, €80 to €160; X-rays, €60 to €150. A dental clean with X-rays and anaesthetic, €180 to €400, and with extractions €300 to €900 or more. Permethrin poisoning with hospitalisation and seizure control can cost from €300 to over €1,000 depending on severity. Removing a linear foreign body from the intestine is abdominal surgery that usually costs €800 to €2,000.
What not to do
Do not pull a thread coming from the mouth or bottom. Do not put your fingers deep into its mouth if it is drooling from pain: it may bite you without meaning to, and cat bites become infected very easily. Do not make it vomit with salt, hydrogen peroxide or anything similar if you think it has eaten something toxic: in cats it does not work well and can cause serious injury. Do not give it milk as an “antidote”. And never apply a dog spot-on to a cat: many contain permethrin, which is harmless to dogs and highly toxic to cats.
Prevention
Put away threads, hair bands, ribbons, fishing line and tinsel; games with wand toys and strings should always be supervised and then go back in a drawer. Check which plants you have at home and remove the toxic ones, starting with any lily. Use only parasite treatments made for cats, and if a cat lives with a dog treated with permethrin, keep them apart until the spot-on has dried. Keep cleaning products tightly closed and rinse floors well. And look after its mouth: dental check-ups at least once a year, brushing if it accepts it, and attention to any change in how it eats or how its breath smells. The mouth is the most common cause of drooling, and also the easiest to prevent.
Drooling with pleasure on your lap is normal. Sudden drooling usually means mouth pain, a thread or foreign body, a toxin or nausea. If it comes with tremors, a suspected toxin or a visible thread, go to the emergency vet; never pull the thread or make it vomit at home.
Educational content from Michipedia, translated from the Spanish original. It does not replace the advice of a vet or a feline behaviour specialist. Every cat is an individual.