Can Your Cat Make You Sick? The Surprising Truth


Cats make wonderful pets and provide companionship to millions of people. However, some health risks do exist with cat ownership. According to the CDC, over 400,000 cat bites occur in the United States each year that require medical attention. While rare, cats can transmit diseases to humans that may cause mild to serious illness. Toxoplasmosis infects around 11% of the US population, often contracted through exposure to cat feces. Understanding the potential health hazards can help cat owners take precautions and know when to seek medical care.

Common Cat-Related Health Issues

Cats can potentially transmit diseases to humans, especially people with weakened immune systems. Some of the most common cat-related health issues that may affect humans include:


Toxoplasmosis is caused by a parasite called Toxoplasma gondii. Cats are the main host for this parasite. Humans can contract toxoplasmosis by ingesting contaminated food or water, eating undercooked meat, or exposure to cat feces that contain Toxoplasma eggs (CDC). If a pregnant woman becomes infected, it can be passed to the unborn child. Most healthy adults infected show no symptoms, but it can cause flu-like symptoms. In people with compromised immune systems, it can cause damage to the brain, eyes, and other organs.

Cat Scratch Disease

Cat scratch disease is caused by a bacterium called Bartonella henselae. As the name suggests, it is usually transmitted through a bite or scratch from an infected cat. Symptoms include swollen lymph nodes, fatigue, fever, and headaches. It usually resolves on its own, but antibiotics may be prescribed in some cases (Just Cats Clinic).


Allergies to cats are among the most common allergies. Symptoms include coughing, sneezing, watery eyes, runny nose, and itchy skin. This is caused by an immune reaction to proteins found in cat dander, saliva, or urine. Keeping the cat out of bedrooms and frequent cleaning can reduce allergen levels, but some people need to re-home their cats.


Cats can worsen asthma symptoms in people with allergies. Asthma is characterized by difficulty breathing, wheezing, chest tightness, and coughing. Cat allergens can trigger asthma attacks. Managing cat allergies and asthma involves taking medication, avoiding triggers, and keeping cats out of bedrooms.


Toxoplasmosis is caused by a parasite called Toxoplasma gondii. This parasite is found in cat feces that have not been disposed of properly. According to the CDC, the overall seroprevalence of T. gondii in the United States population 6 years and older is 11% (CDC, Though most people infected by T. gondii show no symptoms, toxoplasmosis infection can be dangerous for pregnant women and those with weakened immune systems.

When a pregnant woman is newly infected with T. gondii, the parasite may be passed to the developing fetus. This could result in serious health problems such as hearing loss, intellectual disabilities, and blindness (CDC). For those with weakened immune systems, such as people with HIV/AIDS, toxoplasmosis infection can cause brain inflammation and damage.

While toxoplasmosis poses health risks for some groups, it is not considered overly dangerous for healthy adults. Proper precautions should be taken, however, such as wearing gloves when cleaning the litter box, washing hands afterwards, and keeping cats indoors to avoid infection from hunting and exposure to outdoor feces.

Cat Scratch Disease

Cat scratch disease is caused by a bacteria called Bartonella henselae, which cats may carry in their mouths or on their claws. The bacteria can be transmitted to humans when a cat bites or scratches them, breaking the skin and allowing the bacteria to enter. According to a 2016 study, cat scratch disease causes around 12,000 hospital visits every year in the United States, with the highest incidence in the southern states and in children aged 5-9 years old [1].

Once transmitted, the bacteria travel through the lymphatic system and multiply in the lymph nodes closest to the original bite/scratch. This causes the lymph nodes to become swollen and inflamed. Common symptoms include fever, fatigue, and enlarged or tender lymph nodes around the head, neck, or upper limbs [2]. While cat scratch disease often resolves on its own, antibiotics may be prescribed in severe cases to clear the infection faster.


Allergies are one of the most common health issues caused by cats. Approximately 10-20% of people are allergic to cats globally (a figure that has been increasing) [1]. The allergies are caused by a protein called Fel d 1 that is found in cat saliva and skin/dander [2]. When a person with a cat allergy is exposed to this protein, their immune system overreacts and releases histamine, causing allergy symptoms.

Common allergy symptoms from cat exposure include sneezing, runny nose, watery eyes, itchy nose/throat/eyes, coughing, postnasal drip, and facial pressure and pain. More severe symptoms may include difficulty breathing, chest tightness, wheezing, and hives. The immune response and symptoms usually begin 10-20 minutes after exposure to a cat and can last for hours afterwards [3].


Cat allergens can trigger asthma attacks, especially in children with cat allergies. According to research from PubMed, exposure to cat allergens can worsen asthma symptoms, decrease peak expiratory flow, and increase the need for asthma medication in children who are allergic to cats, even with indirect exposure like at school.

The American Lung Association warns that exposure to cat dander and saliva can trigger asthma symptoms and episodes in sensitive individuals. They recommend keeping cats out of bedrooms and limiting fabric surfaces that collect allergens. Some research suggests early life exposure to cats may reduce later asthma risk, but parents should be cautious if a child already has asthma or allergies.

Mitigating Risk

There are several steps cat owners can take to reduce the risk of contracting an illness from their cat:

Keep cats indoors. Indoor cats are less likely to contract and transmit diseases than cats that go outdoors. Restrict your cat’s access to the outdoors to avoid exposure to other animals and infectious agents.

Clean litter boxes frequently. Scoop waste from the litter box daily and change the litter regularly to prevent the spread of toxoplasmosis and other parasites. Wear gloves while cleaning and wash hands afterwards.

Wash hands after contact. Thoroughly wash hands with soap and water after handling cats, cleaning up after them, or touching areas they frequent. Proper hygiene is key to preventing transmission.

Brush cats frequently. Regular brushing helps remove allergens like dander from your cat’s coat so they don’t spread around your home. This can provide some relief to those with cat allergies.

See your veterinarian for regular checkups and keep your cat’s vaccines and parasite control up to date. A healthy cat is less likely to harbor and transmit diseases.

When to See a Doctor

As cat owners, it’s important to be aware of the signs that indicate your cat may require medical attention. Persistent flu-like symptoms, including lethargy, appetite loss, and fever that do not resolve on their own within a couple days warrant a trip to the veterinarian (Hillcrest Animals, 2020). Respiratory problems like labored breathing, wheezing, and coughing should also prompt an urgent vet visit, as these could indicate potentially serious conditions like asthma, pneumonia, or heart disease.

Additionally, any skin lesions, redness, swelling or pus around scratches or bites should be evaluated right away, as they may be indicative of infections like cat scratch fever/disease or ringworm that require treatment (VCA Hospitals, n.d.). At the first signs of major and persistent changes in your cat’s health or behavior, do not hesitate to consult your veterinarian, as timely treatment greatly improves outcomes.

Alternatives if Re-Homing

If your allergies are mild, there are some alternatives to re-homing your cat that may allow you to keep living together comfortably:

Some cat breeds like the Siberian, Russian Blue, and Devon Rex produce less of the Fel d 1 protein that causes allergies in humans. Getting a hypoallergenic cat breed may reduce allergy symptoms.

Allergy shots can help build immunity to cat allergens over time. Getting regular allergy shot immunotherapy from an allergist may increase your tolerance to cats.

Keeping your cat out of the bedroom can reduce exposure to allergens during sleep. Use air purifiers and practice diligent cleaning to reduce allergens in the rooms your cat is allowed.


To recap the main points in this article, illnesses caused by cats are real, though relatively uncommon concerns for most cat owners. The most serious risks come from toxoplasmosis and cat scratch disease, which can cause dangerous symptoms in people with weakened immune systems. Allergies and asthma are also common cat-related conditions that range in severity.

However, the overall risk of becoming seriously ill from a household cat is low for most people. Taking precautions like washing hands after contact, avoiding scratches/bites, cleaning the litter box daily, and keeping cats indoors can greatly reduce potential health hazards. Consulting a doctor about your specific level of risk and susceptibility to various conditions can provide helpful insight as well.

For those unable to live with cats due to allergies or other medical risks, alternatives like finding a new home for the cat or using medication to manage symptoms may be options worth discussing with your doctor. With some awareness and care taken, cats can be enjoyed with minimal health concerns by many people.

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