Feline Foes. 3 Dangerous Diseases You Can Catch from Cats


Zoonotic diseases, also known as zoonoses, are infectious diseases that spread between animals and humans. These diseases can be caused by bacteria, viruses, parasites, and fungi that animals carry but rarely get sick from. Cats are natural reservoirs for many zoonotic pathogens that can infect humans through various forms of contact. According to the CDC, over 60% of known infectious diseases in people can be spread from animals. Some of the most concerning zoonotic diseases that cats can transmit to humans include toxoplasmosis, cat scratch disease, ringworm, rabies, salmonella, campylobacter, cryptosporidiosis, and roundworm.


Toxoplasmosis is a disease caused by a parasite called Toxoplasma gondii. Cats are the definitive host for T. gondii, meaning the parasite reproduces sexually in the cat’s intestine and is shed in their feces (CDC). The Centers for Disease Control and Prevention (CDC) estimates that over 40 million people in the United States may be infected with the Toxoplasma parasite (CDC).

Cats shed the parasite in their feces and if humans ingest anything contaminated with infected cat feces, such as soil, water, or food, they can become infected. Pregnant women are at risk of transmitting the infection to their unborn child. Other high risk groups are people with weakened immune systems, such as those with HIV/AIDS. According to the CDC, toxoplasmosis is one of the leading causes of death attributed to foodborne illness in the United States (CDC).

In humans, toxoplasmosis can cause flu-like symptoms like swollen lymph nodes and muscle aches and pains. In people with weakened immune systems and infants born to infected mothers, toxoplasmosis can cause more serious symptoms such as brain and eye damage. There is no vaccine or medications available to prevent toxoplasmosis so the best way to avoid infection is through proper hygiene, washing hands before meals, washing all fruits and vegetables, and avoiding ingesting anything that has come into contact with cat feces (CDC).

Cat Scratch Disease

Cat scratch disease (CSD), also known as cat scratch fever, is a bacterial disease that can be transmitted from cats to humans. It is caused by the bacterium Bartonella henselae, which cats can carry in their blood, saliva, and under their claws.

Cats can transmit B. henselae to humans through scratches, bites, or by licking an open wound. The disease occurs most commonly in children and immunocompromised adults. According to a 2016 study published in Emerging Infectious Diseases, the annual incidence of CSD in the United States between 2005-2013 was approximately 4.7 cases per 100,000 persons under the age of 65. The incidence was highest among children 5-9 years old.

Symptoms of CSD usually begin 3-10 days after exposure. They include fever, headache, fatigue, and swollen lymph nodes near the scratch or bite. A rash may also develop at the wound site. In most cases, symptoms resolve on their own within 2-4 months. However, complications like encephalitis, endocarditis, and osteomyelitis can occur in 5-10% of patients. Antibiotics can help treat severe cases of CSD.

To help prevent CSD, it’s important to avoid rough play with cats and kitten scratches. Cats should also be kept up-to-date on vaccines and flea/tick control to reduce the chance of them transmitting B. henselae. Promptly cleaning any cat scratches or bites with soap and water can also lower infection risk.


Ringworm is a contagious fungal infection that cats can transmit to humans (VCA Animal Hospitals). The infection is caused by dermatophyte fungi that feed on keratin, a protein found in skin, hair, and nails. Spores from these fungi can survive for long periods in the environment. Ringworm gets its name from the ring-shaped rash that develops on the skin or scalp.

Cats become infected through direct contact with spores from an infected animal or environment. The spores take hold and multiply, causing ring-shaped lesions that can appear anywhere on the body. Kittens and cats with weakened immune systems are more susceptible (PetMD).

Ringworm spreads between cats through direct contact or by contact with contaminated objects like bedding. The fungi can survive on surfaces and infected hair that sheds from the cat. Humans can catch ringworm by petting or handling an infected cat.

Treatment involves antifungal medications, both oral and topical. The environment must also be decontaminated. With proper treatment and precautions, ringworm can be cured in 4-8 weeks. Humans can use over-the-counter antifungals to treat ringworm caught from cats.


Rabies is a fatal viral disease that can affect all mammals, including cats and humans (CDC, 2022). The rabies virus is transmitted through saliva, usually from the bite of an infected animal. In the U.S., domestic animals accounted for only 7.6% of reported rabies cases in 2015 (Alley Cat Allies, 2017).

Rabid cats may show a variety of symptoms including fearfulness, aggression, excessive drooling, difficulty swallowing, paralysis, seizures, and death. However, rabies transmission from cats to humans is extremely rare. No cat-to-cat transmission has been recorded, and no cat-specific rabies virus strain is known to exist (Merck Veterinary Manual, 2022).

If a human is potentially exposed to rabies from a cat, immediate medical attention including vaccination is required. But overall, rabies is uncommon in pet cats due to widespread vaccination. Stray cats are at higher risk of exposure.


Salmonella is a genus of bacteria that can cause gastrointestinal illness in humans and animals. Cats can become infected with Salmonella through ingesting contaminated food or water, and the bacteria is shed in their feces (petMD). There are many different species of Salmonella, with over 2,000 serotypes identified. Salmonella infection in cats is known as salmonellosis.

When a cat is infected with Salmonella, the bacteria multiples in the intestinal tract and is passed in the feces. The main symptoms are diarrhea, vomiting, fever, and lethargy. Dehydration can also occur if the diarrhea is severe. Most cats recover fully with treatment, but salmonellosis can be fatal in rare cases, especially in kittens and older cats with weakened immune systems.

Cats shed Salmonella in their feces intermittently after infection, even if they show no symptoms. This makes litter boxes a prime transmission source. Humans can become infected through contact with contaminated feces or litter. To prevent human transmission, litter boxes should be cleaned daily, wearing gloves and washing hands afterwards. Keeping litter boxes away from food preparation areas is also important (WagWalking).

Other prevention measures include keeping cats indoors to avoid hunting/scavenging behaviors that could lead to infection. Cats should also be fed commercially prepared food instead of raw diets that may contain Salmonella. Prompt treatment of diarrheal illnesses can reduce shedding. Testing and treating cats identified as chronic Salmonella carriers may also help reduce transmission.


Campylobacteriosis is caused by the bacteria Campylobacter and is one of the most common bacterial infections that humans can get from cats. Campylobacter bacteria are found in the intestines of cats and can be shed in their feces. Humans can become infected if they come into contact with infected feces, such as when cleaning a litter box.1

In cats, Campylobacter infection often causes diarrhea, but some cats may not show any symptoms. However, even asymptomatic cats can still shed the bacteria in their feces and infect humans.2 In humans, Campylobacteriosis typically causes severe gastrointestinal symptoms including abdominal pain, cramping, nausea, and watery or bloody diarrhea.3 In rare cases, it can produce more serious complications such as reactive arthritis or Guillain-Barré syndrome.

To reduce the risk of Campylobacteriosis from cats, it is important to practice good hygiene such as washing hands after cleaning litter boxes and avoiding contact between cats and food preparation areas. Keeping cats up-to-date on deworming can also help reduce shedding of the bacteria.


Cryptosporidiosis is an intestinal disease caused by a protozoan parasite called Cryptosporidium felis. The parasite is spread through ingestion of contaminated food or water. Cryptosporidium infects the cells lining the small intestine, causing diarrhea. The disease is highly contagious and can spread quickly between cats in multi-cat households.

In most cases, cryptosporidiosis causes acute but self-limiting diarrhea in cats. However, kittens and cats with weakened immune systems can develop more severe, life-threatening diarrhea. Dehydration is a major concern. There is no specific drug treatment for cryptosporidiosis in cats. Supportive care with fluids and medications to control vomiting and diarrhea are important. The parasite can be difficult to eliminate from the environment.

Cryptosporidium felis poses little zoonotic risk to healthy humans. However, immunocompromised individuals are at higher risk of infection. Preventive measures include keeping litter boxes clean, washing hands after contact with cat feces, avoiding contamination of food and water, and not allowing cats to lick around human mouths.





Roundworm, also known as Toxocara cati, is an intestinal parasite that commonly infects cats. Cats become infected by ingesting eggs in contaminated soil or the feces of other cats. The eggs hatch in the cat’s intestine, and the larvae migrate through the body and encyst in tissues.

Cats may show no symptoms of a Toxocara infection. However, heavy worm burdens can cause vomiting, diarrhea, distended belly, and poor growth. Kittens tend to be more severely affected than adult cats.

Humans can become infected by ingesting infective eggs, often by contacting contaminated soil or surfaces. Children are at highest risk due to behavior like eating dirt. In humans, larvae migrate through tissues and can cause damage to organs like the liver or eyes. This condition is called toxocariasis or visceral larva migrans. Symptoms may include vision loss, rash, fever, cough, abdominal pain, nausea, asthma-like wheezing.

To prevent human infection, prompt removal of cat feces from soil, washing hands after cleaning litter boxes, and preventing cats from accessing children’s play areas are recommended. Regular deworming of cats can also reduce environmental contamination with eggs. If infection occurs in humans, antihelminthic drugs may be prescribed.

For more information, see:

Toxocara cati Infection in Cats

CDC Toxocariasis FAQs


In summary, there are several diseases that humans can contract from cats. The most common include toxoplasmosis, cat scratch disease, ringworm, rabies, salmonella, campylobacter, cryptosporidiosis, and roundworm.

Many of these diseases can be prevented through proper hygiene and care. It’s important for cat owners to wash hands after handling cats, especially before eating. Kittens should be tested for diseases and properly vaccinated. Litter boxes should be cleaned daily and proper precautions taken when cleaning. Cats should also be treated monthly with flea/tick medication.

While there are risks associated with cat ownership, taking the right precautions can greatly reduce the likelihood of contracting any diseases. With proper care and veterinary care, cats can be very safe companions.

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