Introduction
Cats use their tongues for grooming, cleaning, and showing affection. As any cat owner knows, kitties love to lick their owners’ hands, faces, and other exposed skin. While this behavior may seem cute and harmless, some people worry that cat saliva could pose health risks to humans. Concerns around toxicity and infection from cat saliva date back centuries, though the science is still inconclusive. With over 94 million pet cats in the US alone, it’s an important issue for cat lovers to understand.
Cats’ Saliva Contains Bacteria
Cats’ mouths contain bacteria that can potentially be harmful to humans. One common bacterium found in cats’ saliva is Pasteurella multocida. According to a CBC News article, Pasteurella multocida bacteria can cause infections in humans after a cat bite or scratch (source). Another bacterium commonly present in cats’ saliva is Capnocytophaga. The CDC reports that Capnocytophaga bacteria live in cats’ mouths without making them sick, but can rarely infect humans after a bite or close contact with a cat’s saliva (source).
Potential Health Risks
Cat saliva contains bacteria that can cause infections if transmitted to humans. Some of the main health risks include:
Cat scratch disease – Caused by the bacteria Bartonella henselae, cat scratch disease leads to swollen lymph nodes and fever after a cat scratch or bite breaks the skin and exposes a person to the bacteria. It is usually mild in healthy people but can be more severe in those with compromised immune systems (source).
Cat bite infections – Bites that puncture the skin can lead to bacterial infections, either locally or systemically. Common bacteria involved include Pasteurella, Staphylococcus, Streptococcus, and others. Infections require antibiotic treatment and can become serious if left untreated (source).
Severe systemic infections – In rare cases, the bacteria Capnocytophaga canimorsus from cat saliva can transmit through bites/scratches and cause severe sepsis, especially in those with weakened immune systems or no spleen (source).
Transmission to Humans
Cats can transmit bacteria to humans through bites, scratches, or licks that come into contact with open wounds or mucous membranes. The main bacteria of concern are Bartonella henselae and Capnocytophaga canimorsus. Bartonella henselae is the bacteria that causes cat scratch disease and can be found in cat saliva (1). This bacteria does not make cats sick but can infect humans when transmitted through a bite or a scratch. Capnocytophaga canimorsus is also commonly found in cat saliva and can cause rare but serious infections in humans (2).
When a cat licks an open wound on a human, its saliva can introduce bacteria into the wound. Scratches and bites that break the skin also create an entry point for bacteria to get inside the body. For people with weakened immune systems, this can lead to infections. Kittens are more likely to transmit Bartonella henselae than adult cats (3). Overall, cat owners should be aware of potential bacterial transmission through saliva contact and take precautions as needed.
Symptoms in Humans
Cat scratches or bites can transmit bacteria that cause infection in humans. According to the CDC, the infected area usually appears swollen and red with round, raised lesions and can have pus [1]. A person with a cat saliva infection may also develop flu-like symptoms such as:
- Fever
- Headache
- Poor appetite
- Fatigue
- Joint pain
If the bacteria enter the bloodstream, more severe symptoms can occur. Johns Hopkins Medicine reports that cat scratch disease can cause infections affecting the brain, eyes, heart, liver, spleen, joints, bones, and lymph nodes [2]. Proper treatment is important to prevent dangerous complications.
At-Risk Groups
Young children, the elderly, and immunocompromised individuals are most at risk for developing illnesses from cat saliva exposure. Cat saliva contains bacteria that can be especially harmful to those with weaker immune systems.
Young children do not yet have fully developed immune systems, so their bodies have a harder time fighting off infections that may occur from a cat scratch or bite. The elderly also tend to have weaker immune systems due to age, making them more vulnerable as well.
Those with immunocompromising conditions like HIV/AIDS, cancer, diabetes, or those taking immunosuppressant medications also have a high risk for illness from cat saliva. Their compromised immune systems cannot fend off infections as effectively.
According to the CDC, over 90% of people who develop severe Capnocytophaga infections have a pre-existing immunocompromising condition. Other at-risk groups include alcoholics and those without a spleen, since the spleen helps fight bloodstream infections.[1]
All people should use caution around cats, but these higher risk groups need to be especially vigilant. Prompt treatment is crucial for those exposed who may have weaker immune defenses against the bacteria present in cats’ mouths.
Treatment
Treatment for cat scratch disease focuses on managing symptoms and preventing complications. Antibiotics are not always necessary, but may be prescribed in some cases. According to the Centers for Disease Control and Prevention, antibiotics can shorten the duration of lymph node swelling and fever in adults [1].
Wound care is important for cat scratches and bites to prevent infection. The wound should be washed thoroughly with soap and water. Over-the-counter antibiotic ointment can be applied. A tetanus shot may be recommended if you haven’t had one in the past 5 years [2].
Most symptoms can be managed with rest, fluids, and over-the-counter pain and fever relievers like acetaminophen. Applying warm compresses to swollen lymph nodes may help relieve discomfort.
Prevention
There are several steps that can be taken to prevent infections from cat saliva and scratches:
Avoid rough play and petting that could lead to bites or scratches. Supervise children carefully when playing with cats. Cats may bite or scratch when overstimulated. Teach children safe ways to play without excessive roughhousing. [1]
If scratched or bitten, immediately clean the wound thoroughly with soap and running water. This helps remove bacteria and prevent infection. [2] Do not allow cats to lick open wounds, as their saliva can introduce bacteria.
Keep cats’ nails trimmed to minimize scratches. Declawing is controversial but may be considered to prevent serious scratches in some cases.
Careful play and handling can reduce bites and scratches. Supervise children and avoid overly rough play. Properly socializing cats can make them less prone to bite and scratch.
When to See a Doctor
If you develop signs of infection after a cat bite or scratch, it’s important to see your doctor for prompt treatment. Signs of infection include:
- Fever
- Swelling, redness, warmth around the bite or scratch
- Pus or oozing from the wound
- Red streaks extending from the wound
- Swollen lymph nodes near the wound
Other symptoms like fatigue, headache, joint pain, and loss of appetite could also indicate infection. Seek emergency care if you have difficulty breathing, a high fever, or the redness and swelling spread quickly.
Antibiotics are used to treat cat scratch disease and prevent serious complications. Your doctor may drain and clean the wound and prescribe antibiotics to clear the infection. Prompt treatment can help prevent the infection from spreading or damaging your joints, heart, brain, or other organs.
Monitor any cat scratches or bites carefully and don’t hesitate to call your doctor if signs of infection develop. Prompt antibiotic treatment is key to a fast and full recovery.
Conclusion
In summary, cat saliva does contain bacteria that can pose health risks to humans. While cat bites and scratches can cause infections like cat scratch fever, even cat saliva contacting broken skin or entering the body through the mouth or nose can potentially transmit disease. At-risk populations like young children, the elderly, pregnant women, and those with weakened immune systems should take extra care around cats.
However, the risks can be managed through proper precautions. Getting cats vaccinated, avoiding rough play, washing hands after contact, and seeking medical care for any bites or scratches can help prevent infections. While cat saliva should be handled carefully, overall the benefits of cat companionship often outweigh the risks for most cat owners.
