While drooling might be a totally normal, everyday thing for dogs, seeing your cat suddenly start to slobber is usually cause for concern. So, why exactly do cats drool?

Although occasional drooling can be a perfectly normal reaction in certain situations, it can also be a red flag for an underlying illness, injury, or even a medical emergency. As a responsible pet parent, understanding the reasons behind your cat's drooling—and knowing when to call the vet—is crucial for their health and well-being. In this article, we’ll break down the various causes of cat drooling and provide helpful tips on what you should do next.

Why Is My Cat Drooling?

There are plenty of reasons why your cat might be drooling. While some are perfectly normal, others could point to a medical emergency. Let's break this down into two main categories.

Normal Reasons for Drooling

If you notice your cat only drooling a little bit now and then, and they are otherwise acting like their usual self, there is generally no need to panic. Here are a few common, harmless reasons:

Ultimate Relaxation and Happiness: A lot of cats will involuntarily drool when they are getting pet, purring, or "making biscuits" (kneading). This is usually tied back to their kittenhood memories of nursing. When your cat feels incredibly safe and relaxed, their brain releases endorphins that stimulate their salivary glands. If your cat has been doing this since they were little—and it only happens when they are super happy—it is just a really cute, perfectly normal quirk. 

Fear and Anxiety: On the flip side, extreme stress can also trigger the release of endorphins and cause your cat to drool. For instance, if they get motion sickness in the car, are taking a stressful trip to the vet, or find themselves in a totally unfamiliar environment, high anxiety can bring on the drool. You will usually see this paired with "airplane ears" (ears pinned flat back), distressed meowing, or attempts to escape. Once the stressful situation is over, the drooling should stop right away.

Abnormal Reasons for Drooling (When to Call the Vet)

If your cat’s drooling comes on suddenly, is excessive, or happens alongside other unusual behaviors, it is considered abnormal (or pathological) and requires immediate attention. Here are the most common medical reasons for a drooling cat:

1. Dental Disease

This is one of the top culprits for abnormal drooling in cats. Tartar buildup, gingivitis, periodontal disease, or severe mouth ulcers can be incredibly painful. On top of that, oral tumors or loose teeth can make swallowing difficult, causing drool to spill over.

Symptoms to watch for: Unusually bad breath (halitosis), blood-tinged drool, a drop in appetite, or pawing at the mouth or cheeks.

2. Nausea and GI Upset

When cats feel nauseous, they often drool to help soothe an upset stomach. Nausea can be triggered by several things, including motion sickness, struggling to pass a hairball, or a gastrointestinal infection.

Symptoms to watch for: Vomiting, dry heaving/retching, and a noticeable loss of appetite.

3. Toxins and Poisons

Cats are highly sensitive to many common household items and plants. Toxic plants like lilies and pothos, as well as cleaning supplies or pest control chemicals, can severely irritate a cat's mouth and esophagus if licked or ingested. Some toxins act directly on the nervous system, leading to heavy drooling.

What to do: If you suspect your cat has gotten into something toxic, call your emergency vet or a pet poison helpline immediately—this is a life-threatening emergency.

4. Foreign Objects

While playing or eating, things like yarn, bone splinters, needles, or plant thorns can easily get wedged between their teeth, under their tongue, or deep in their throat. The intense pain and the inability to close their mouth or swallow will cause continuous drooling.

5. Bitter Reactions to Medications

Many medications that are perfectly safe for cats happen to taste awful to them. When you give them liquid meds or pills, the bitter taste can shock their taste buds, causing them to drool profusely or even foam at the mouth for a short time. This is usually temporary and nothing to panic about. However, if pilling your cat becomes too stressful, ask your vet about compounding the medication into a different form or flavor.

6. Underlying Systemic Illnesses

As cats get older, liver or kidney failure (like chronic kidney disease) can cause toxins to build up in the bloodstream (uremia). This can make them chronically nauseous or cause painful ulcers to form in their mouths, both of which lead to non-stop drooling.

7. Heatstroke

Unlike dogs, cats don't typically pant to cool down. If your cat is in a hot environment (like a sunroom or a parked car in the summer) and suddenly starts open-mouth breathing, panting heavily, and drooling, these are major red flags for heatstroke. You need to cool them down immediately and rush them to the vet.

8. Rabies

While it is extremely rare in vaccinated cats, one of the classic signs of rabies is uncontrollable drooling. Infected cats will also show severe neurological issues and sudden, drastic changes in behavior. To keep everyone safe, it is absolutely crucial to keep your cat up-to-date on their rabies vaccines.

When to Call the Vet?

Cats are absolute masters at hiding pain. By the time you actually notice they're uncomfortable, the underlying issue has usually already progressed. If you spot any of the following signs, call your vet right away to schedule an appointment:

Sudden, continuous drooling: This is especially concerning if your cat isn't typically a drooler.

Abnormal drool: Watch out if their saliva has a foul odor, is blood-tinged, or looks yellowish-green.

Trouble eating: Your cat acts hungry but can't seem to chew, or they are completely refusing food and water.

Behavioral changes: Look out for severe lethargy, hiding, or just a general lack of energy.

Rapid breathing or severe vomiting: These are major red flags that could indicate poisoning or organ damage.

Final Thoughts

When it comes to the question of "Why do cats drool?", the answers can range from something as sweet as being completely relaxed and happy around you, to something as critical as poisoning or a severe illness. As responsible pet parents, it's up to us to look at the big picture, taking both their immediate environment and any other physical symptoms into account.

In your day-to-day routine, you can prevent the vast majority of drool-causing medical issues by regularly brushing your cat's teeth, keeping up with their annual vet exams, and making sure all toxic houseplants and dangerous household chemicals are safely out of reach. If you're ever unsure, just remember this golden rule: if something seems off, get them to the vet immediately. A professional diagnosis is always the best way to keep your furry friend safe and healthy.