Cat kennel cough is technically contagious to humans, but the risk is extremely low for anyone with a healthy immune system. The bacterial component of feline respiratory disease, Bordetella bronchiseptica, is the one pathogen that can jump from cats to people. It rarely does. The viruses that cause most feline upper respiratory infections, including feline calicivirus and feline herpesvirus, pose no threat to humans at all.
Which Pathogen Can Actually Spread
What people call “kennel cough” in cats is usually a mix of infections. The two most common viral culprits are feline calicivirus and feline herpesvirus. Neither of these can infect humans. Feline calicivirus belongs to the same broad virus family as human norovirus, but the feline version is species-specific. Cornell University’s veterinary college confirms it poses no threat to people.
The one organism worth paying attention to is Bordetella bronchiseptica, a bacterium that causes kennel cough in dogs, respiratory disease in cats, and “snuffles” in rabbits. Unlike the viruses, Bordetella bronchiseptica is the least host-restricted member of its bacterial group, meaning it can cross between species. It spreads through inhaled aerosol droplets: when a sick cat sneezes or coughs, tiny particles containing the bacteria can enter your nose, mouth, or eyes.
How Likely You Are to Get Sick
For a healthy adult, the odds are vanishingly small. Bordetella bronchiseptica rarely infects healthy humans. Documented human infections have almost exclusively occurred in immunocompromised patients with direct animal contact. In one reported case published in the journal CHEST, a kidney-pancreas transplant recipient on immunosuppressive medications developed Bordetella pneumonia after exposure to her recently vaccinated dogs. Cases like this illustrate the risk but also highlight how narrow the vulnerable population is.
If a healthy person did somehow contract Bordetella bronchiseptica, it would typically produce a mild, whooping-cough-like syndrome: a persistent cough, possibly some upper respiratory congestion, but nothing life-threatening. In immunocompromised individuals, the infection can occasionally become more serious, with rare complications including pneumonia, heart valve infections, and meningitis.
Who Should Be More Careful
The people who need to take this risk seriously are those with weakened immune systems. That includes people undergoing chemotherapy, organ transplant recipients on anti-rejection drugs, individuals with uncontrolled HIV/AIDS, and anyone on long-term immunosuppressive therapy for autoimmune conditions. If you fall into one of these categories and your cat develops a persistent cough, sneezing, nasal discharge, or other signs of respiratory illness, it’s worth having the cat seen by a vet promptly and minimizing close face-to-face contact until the infection clears.
How Transmission Happens
A sick cat spreads respiratory bacteria primarily by coughing and sneezing, which sends droplets into the surrounding air. You can inhale these directly. Bacteria can also end up on the cat’s fur during grooming and transfer to your hands when you pet or handle the cat. From there, touching your face completes the chain. Contaminated surfaces like food bowls, bedding, and litter boxes can harbor pathogens as well, though this is a more indirect route.
Cats in crowded environments like shelters and multi-cat households are far more likely to carry Bordetella bronchiseptica. If you’ve recently adopted a cat from a shelter and it’s showing respiratory symptoms, that’s the scenario where the bacterium is most likely to be present.
Reducing Your Risk
Basic hygiene is all most people need. Wash your hands after handling a cat that’s visibly sick, especially before touching your face. Keep the cat’s living space clean, including regular litter box maintenance and washing of food and water bowls. If your cat is sneezing frequently, avoid letting it sneeze directly into your face (something most people instinctively avoid anyway).
Keeping cats indoors helps prevent them from picking up respiratory infections from stray or feral animals in the first place. Cornell’s veterinary college recommends indoor living or enclosed outdoor spaces like catios to limit exposure to infectious diseases carried by other animals. Prompt veterinary treatment for a coughing cat also shortens the window during which the bacteria could theoretically spread.
If You Think You’ve Been Exposed
A healthy person who catches a mild cough after caring for a sick cat almost certainly has a common cold or seasonal virus, not Bordetella. But if you’re immunocompromised and develop a persistent cough, especially one that sounds like whooping cough, after close contact with a cat showing respiratory symptoms, it’s worth mentioning the animal exposure to your doctor. Bordetella bronchiseptica is not a common human pathogen, and one of the biggest challenges in human medicine is that doctors don’t always think to test for it. Identifying the correct bacterium matters because standard first-line antibiotics often don’t work against it, while other antibiotic combinations are effective.