The Dangers of Letting Your Cat Lick Your Mouth


Many cat owners allow and even encourage their cats to lick them, finding it an endearing sign of affection. However, some cat owners have concerns about the health implications of letting their cat’s tongue inside their mouth. Cats spend much of their day grooming themselves by licking their fur. While this is a normal feline behavior, it can expose cats to bacteria, viruses, and parasites. These can then be passed on through a cat’s saliva when they lick their owner’s face or mouth.

This article provides an overview of health risks posed by cat licks to the mouth, including diseases cats may transmit as well as precautions owners can take. It also covers when cat owners should see a doctor if concerned about sickness from a cat licking their mouth.

Diseases Cats Can Transmit

While most cats are perfectly healthy, there are some diseases that can be transmitted from cats to humans. The main diseases of concern are:


Toxoplasmosis is caused by a parasite called Toxoplasma gondii. Cats can become infected by eating infected birds or rodents, then shed the parasite in their feces for up to two weeks. Humans can contract toxoplasmosis through inadvertent ingestion of infected cat feces, either by poor hygiene after emptying the litter box, or ingesting contaminated soil or water. Symptoms are typically mild and resemble the flu, but toxoplasmosis can cause serious illness in those with weakened immune systems. Pregnant women should take extra care to avoid infection as it may cause birth defects [1].

Cat Scratch Disease

Cat scratch disease (CSD) is caused by a bacterium called Bartonella henselae that may be carried in the saliva of infected cats. The bacteria are passed to humans through bites or scratches that break the skin. Symptoms include swollen lymph nodes, fever, and fatigue. In rare cases it can lead to more serious complications. Kittens are more likely to spread CSD than adult cats. There is no vaccine or antibiotics to prevent CSD, just proper care of wounds [2].


Pasteurella multocida is a bacterium commonly found in the mouths of healthy cats. Infected cats typically show no symptoms, but the bacteria can cause skin infections in humans if it enters the body through a bite or scratch wound. Pasteurellosis leads to redness, swelling, and pus at the wound site, and may cause more serious issues if the infection spreads. Prompt cleaning of any wound caused by a cat bite or scratch can prevent infection [3].


Plague is a rare but serious bacterial disease caused by Yersinia pestis. Domestic cats can become infected through fleas or by eating infected rodents. Infected cats may show symptoms like swollen lymph nodes, fever, and lethargy. The bacteria can spread to humans via flea bites or direct contact with infected animals. Plague causes fever, chills, weakness, and swollen lymph nodes, and can be fatal if left untreated. Prompt antibiotic treatment greatly improves outcomes [4].


Toxoplasmosis is caused by the Toxoplasma gondii parasite. Cats are the definitive host for T. gondii and the parasite reproduces in the cat’s intestines. An infected cat sheds T. gondii oocysts in its feces which can then infect other animals, including humans. T. gondii oocysts mature in 1-5 days after being shed in feces and then become infectious.

Humans typically contract toxoplasmosis by ingesting infectious T. gondii oocysts through exposure to contaminated cat feces and litter boxes or by consuming undercooked meat. While T. gondii can also be present in cat saliva, transmission via cat licks is rare. According to the CDC, “human infection acquired through direct contact with cats is unlikely.”

Most healthy adults who become infected with toxoplasmosis don’t show any symptoms. However, pregnant women need to take precautions as toxoplasmosis can cause birth defects and miscarriage. People with weakened immune systems are also at risk for more severe symptoms like lung, heart or brain problems from toxoplasmosis.

Indoor cats who only eat canned or dried commercial food are unlikely to ingest T. gondii cysts and become infected. Keeping cats indoors and away from prey reduces their risk. Proper litter box hygiene, washing hands after cleaning litter boxes, washing fruits/vegetables, and fully cooking meat can prevent human infection. Pregnant women should avoid handling litter boxes.


Cat Scratch Disease

Cat scratch disease is caused by a bacterium called Bartonella henselae. This bacteria is commonly found in the saliva of infected cats. Transmission to humans usually occurs when an infected cat scratches, bites, or licks broken skin, allowing the bacteria to enter the body. According to the CDC, approximately 12,000 cases of cat scratch disease are reported each year in the United States. Most infections occur in people under the age of 21, likely due to more frequent exposure to cats [1].

The most common early symptoms of cat scratch disease include swelling and redness at the site of the scratch or bite. This is often followed by fever and enlarged lymph nodes near the affected area. In some cases, more severe complications can develop such as inflammation of the brain or spinal cord, damage to the eyes, or abscesses in internal organs. However, most people fully recover within 2-4 months without any serious effects [2].

There is no vaccine available to prevent cat scratch disease. The best protection is to avoid rough play with cats and kittens that could lead to bites or scratches. Any wounds should be promptly washed with soap and water. Keeping cats free of fleas can also reduce the risk of transmission [3]. If symptoms of cat scratch disease develop after a bite or scratch, seeking prompt medical attention is recommended.



Pasteurellosis is a bacterial disease caused by Pasteurella multocida bacteria. The bacteria usually live in the respiratory system of cats and can enter the human body through scratches, bites, or even licks from a cat (source). Pasteurella multocida is the most common cause of soft tissue infection in humans following cat bites or scratches (source). While typically transmitted through bites, Pasteurella can also enter the body through scratches or even just licks from a cat’s tongue.

Once the bacteria enter the body, they can cause inflammation and infection at the site as well as swollen lymph nodes. Symptoms usually develop within 24 hours and can include redness, pain, swelling, and pus at the site of the bite/scratch. Fever, headache, and swollen lymph nodes may also occur. More serious infections may develop without prompt treatment, such as bone and joint infections, pneumonia, and bloodstream infections.

If the infection is caught early, antibiotics can treat pasteurellosis effectively. Penicillin is usually the first-line treatment, although other antibiotics like amoxicillin-clavulanate, doxycycline, fluoroquinolones, or cephalosporins may also be used (source). Typically a 5-10 day course is prescribed. It’s important for cat owners to watch for signs of infection and seek prompt medical care when necessary.


Plague is an extremely rare but potentially serious bacterial infection caused by Yersinia pestis bacteria. It is usually transmitted through the bite of an infected flea (1). Cats are particularly susceptible to plague and can become infected after being bitten by rodents carrying plague-infected fleas (2).

While rare, cats can potentially transmit plague to humans through scratches, bites, or exposure to respiratory droplets from a sick cat. However, modern antibiotics are highly effective at treating plague if identified early (3). Owners worried their cat may have plague should contact their veterinarian immediately. With prompt treatment, the prognosis for feline plague is good.

Precautions for Cat Owners

While the risks from cat saliva are low for most healthy adults, there are some precautions cat owners can take to reduce potential transmission of disease (PetMD):

  • Have your veterinarian check that your cat is up-to-date on core vaccines like rabies, feline leukemia, and distemper.
  • Deworm your cat regularly as recommended by your veterinarian.
  • Wash your hands after having contact with cat saliva or being licked by your cat.
  • Avoid allowing your cat to lick open wounds, eyes, nose or mouth.

Taking these simple precautions can help reduce any potential health risks from your affectionate feline’s licks and kisses.

When to See a Doctor

In most cases, cat scratches and bites heal on their own without medical intervention. However, it’s important to monitor for signs of infection and see a doctor if any concerning symptoms develop, including:

  • Persistent fever or muscle aches after contact with a cat (1, 2). Fevers over 102°F that last more than 3 days may indicate a bacterial infection like cat scratch disease.
  • Increasing redness, warmth, and swelling around the scratch or bite site, which can suggest a skin infection (2, 3).
  • Red streaks spreading from the wound, a possible sign of blood infection (2, 3).
  • Pus or foul-smelling discharge from the injury (3).
  • Swollen lymph nodes near the scratch or bite (1, 2). This may occur with cat scratch disease.

See a doctor promptly if any of these concerning symptoms develop after a cat scratch or bite. Cat scratches can occasionally lead to more serious bacterial infections that require antibiotics (2, 3). Getting medical attention quickly can help prevent complications.






The risk of disease transmission from a cat licking your mouth is generally low, provided you take basic hygiene precautions and your cat is otherwise healthy. Occasional contact between a cat’s mouth and your own is unlikely to make you sick.

That said, it’s smart to discourage frequent or extended face licking, as saliva can potentially transmit diseases like toxoplasmosis and pasteurellosis in rare cases. Always wash your face after a cat lick. See your vet regularly to keep your cat up to date on vaccines and preventative medicine for parasites.

While transmission is rare, some compromised individuals may be at higher risk from a cat’s saliva. This includes young children, pregnant women, the elderly, and those with weakened immune systems. For these groups, caution is warranted.

Overall the risk is low for most cat owners with healthy cats. Practicing basic hygiene and seeing your vet for preventive care helps minimize any disease transmission risk. An occasional cat lick generally won’t make you sick.


No sources were cited in the writing of this article.

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