Can a Cat Catch a Cold From a Human? What Each Wrong Answer Costs

No. Your cold will not pass to your cat. The standard veterinary references list the causes of feline upper respiratory disease as feline herpesvirus type 1, feline calicivirus, Chlamydia felis, Mycoplasma felis and Bordetella bronchiseptica; human rhinoviruses appear nowhere on that list, and the Merck Veterinary Manual states that the two main feline agents are host-specific and pose no known human risk. Two human respiratory viruses do reach cats. In a Chilean household documented in Emerging Microbes & Infections, the owners tested positive for SARS-CoV-2 on 5 May 2020 and their male cat was showing mild respiratory signs and testing positive two days later. Cats have also been infected with pandemic H1N1 influenza by their owners.

I keep a sample library for an ingredient distributor outside Trieste. Three thousand jars, and every one of them carries two labels: the name the supplier put on the invoice, and the name anybody in the building would actually use. I have spent close to a quarter of a century on that second label, because the first one travels badly across a border. This question is the same problem in a different room. "Cat cold" is one phrase doing duty for two unrelated illnesses, and the cost of mixing them up runs in both directions.

What actually causes a "cat cold"?

Almost always, another cat did. Feline herpesvirus type 1 and feline calicivirus account for the bulk of it, and the herpesvirus is close to universal: the Cornell Feline Health Center reports that up to 97% of cats are exposed in their lifetime, that the virus establishes a lifelong infection in up to 80% of exposed cats, and that up to 45% of those will shed it again periodically, usually when stressed.

That last figure is the one that reframes the question. A cat who has been indoors for six years, met nobody, and starts sneezing the week you did has most likely reactivated something it has carried since kittenhood. Cornell cites shelter data showing 4% of cats shedding herpesvirus on arrival and 50% shedding a week later.

Calicivirus follows the crowd: roughly 10% of cats in small groups are infected, rising to as much as 90% in shelters and breeding catteries. Chlamydia felis turns up in about 20% of cats with upper respiratory signs and about 3% of healthy-looking ones. Bordetella bronchiseptica accounts for around 5% of cats with signs and 1.5% of cats that look normal, and dogs can pass it to cats.

Cat colds and human colds are two illnesses sharing one name

The word "cold" survives the trip between species. Nothing else does. The table below sets the human illness beside the two viruses that cause most of what gets called a cat cold.

| | Human cold (rhinovirus) | Feline herpesvirus (FHV-1) | Feline calicivirus (FCV) | |---|---|---|---| | Who it infects | People | Domestic cats and other felids | Domestic cats | | Incubation | Symptoms build over 2–3 days (NHS) | Signs at 2–6 days after infection (ABCD) | 2–10 days (ABCD, citing Hurley and Sykes) | | How long signs last | Better in about 1–2 weeks (NHS) | Acute disease usually resolves within 10–14 days (ABCD) | Clinical course usually 7–10 days (Merck) | | Signature signs | Sneezing, blocked nose, sore throat | Conjunctivitis, corneal ulcers, fever | Mouth ulcers, drooling, sometimes transient limping | | After recovery | No carrier state | Lifelong infection in up to 80% of exposed cats; up to 45% shed again under stress | Some cats shed for months | | Crosses to the other species | Not documented in cats | Host-specific, no known human risk (Merck) | Host-specific, no known human risk (Merck) |

The mouth is the tell most owners miss. A human cold does not produce tongue ulcers. Calicivirus frequently does, and Merck notes that the drooling and refusal to eat that come with them are often more prominent than anything happening in the nose.

Which human viruses actually do reach cats?

Two, on the published record, and the evidence for each is specific enough to date.

SARS-CoV-2 is the better documented. Emerging Infectious Diseases reported a cat in Belgium that developed a severe respiratory syndrome in March 2020, one week after its owner tested positive. The same journal reported testing of 50 cats from COVID-19 households in Hong Kong, which found six apparent human-to-feline transmissions; the virus sequenced from one cat and its owner was identical, and those cats were healthy. A survey of 919 companion animals in northern Italy, published in Nature Communications, found no animal shedding virus by PCR while 5.8% of cats carried neutralising antibodies. The Chilean household above gives the tightest clock: owners positive on 5 May 2020, the male cat symptomatic and positive two days after that, and two female cats positive four days after him without ever looking ill.

Influenza A is the older and thinner file. Iowa State University researchers reported pandemic H1N1 2009 in a domestic cat in Emerging Infectious Diseases, with human-to-cat transmission presumed, and the European Advisory Board on Cat Diseases lists a string of later reports of cats infected during and after that pandemic, probably direct from their owners. The same guideline is blunt about how little usually follows: experimental infection of cats with low-pathogenic influenza A viruses hardly ever induces disease, and the virus replicates for a few days without signs.

The ABCD recommendation for owners is one sentence long. People with COVID-19 should avoid contact with cats and observe good hygiene to prevent transmitting the virus to them. For cats who normally go outdoors, the same guideline advises letting them continue, on the reasoning that a cat shut in with a sick owner is more exposed, not less.

The four numbers to take before you call the vet

Sneezing on its own tells a vet almost nothing. These figures turn a phone call into a triage.

1. Count the breaths at rest. Cornell puts the ceiling at 35 breaths per minute in a resting cat. Above that, or with visible effort, stop reading and call.
2. Take the temperature. The Merck Veterinary Manual's reference table, adapted from Robertshaw in Dukes' Physiology of Domestic Animals, gives a cat's normal rectal range as 38.1–39.2 °C (100.5–102.5 °F). In feline respiratory disease, Merck notes the fever may reach 40.5 °C (105 °F) before settling and fluctuating around 39 °C (103 °F).
3. Count the missed meals. Cornell's guidance on feline anorexia is that food avoidance can severely affect an adult cat's health once it persists for as little as 24 hours. On a twice-daily feeding schedule, that is two skipped meals. For a kitten under six weeks, 12 hours can be lethal.
4. Look in the mouth and at the eyes. Ulcers on the tongue or hard palate, or a cornea that has gone cloudy, move this out of wait-and-see.

I am not a veterinarian, and I would not want anyone acting on my clinical judgement. What I can vouch for is the value of arriving with numbers instead of adjectives. In my trade the difference between "thickens well" and "1.2% at 60 °C" is the difference between an argument and an order.

How long it lasts, and how long cats stay apart

Merck gives 5–10 days for milder cases of feline respiratory disease and as long as six weeks for severe ones. The ABCD herpesvirus guideline is tighter: signs appear two to six days after infection, and acute disease usually resolves within 10 to 14 days.

Shedding outlasts the illness. Herpesvirus shedding begins as early as 24 hours after infection and continues for one to three weeks, which is why a cat who looks recovered can still infect the cat sharing its water bowl. The ABCD guideline for shelters sets a minimum quarantine of three weeks for incoming cats and says any cat showing signs of infectious disease goes straight into isolation. In a two-cat home the practical version is separate bowls, separate litter, and washed hands, held for three weeks rather than for as long as the sneezing lasts.

For comparison, the NHS says a human cold should be improving within one to two weeks and worth a doctor's attention if it has not improved after ten days.

What being wrong costs, in each direction

Assume you gave it to the cat, and the clock starts running on the wrong illness. You wait for it to pass the way yours will, because that is what colds do. Meanwhile the cat has herpesvirus with a corneal ulcer forming, or calicivirus with mouth ulcers making food painful, and Cornell's 24-hour threshold quietly passes. The vaccination conversation never happens either, and vaccination is the one intervention that reliably reduces the severity of both viruses.

Assume nothing you carry can reach the cat, and you skip a precaution that the evidence supports. That was the Belgian cat, sick a week after its owner's positive test. The traffic in the other direction is small but real: Cornell notes that Bordetella bronchiseptica is transmissible to people in very rare cases, that avian influenza can pass from cats to humans, and that the feline chlamydial agent has caused conjunctivitis in people. None of that is a reason to rehome a cat. It is a reason to wash your hands after cleaning a discharging eye.

The phrase "cat cold" will keep doing double duty, because it is short and everybody understands it until the moment they need it to be precise. In the sample room we solved that by writing both names on the jar. Here the two names are rhinovirus and feline herpesvirus, and only one of them is ever in your house at a time.

Frequently asked questions

Can my cat catch my cold?

No. Human colds are caused mainly by rhinoviruses, which are not among the agents that cause feline upper respiratory disease. What owners call a cat cold is almost always feline herpesvirus or feline calicivirus, picked up from another cat or reactivated from an infection the cat has carried since kittenhood.

Can I catch a cold from my cat?

No. The Merck Veterinary Manual states that feline viral rhinotracheitis and calicivirus are host-specific and pose no known human risk. Two minor exceptions exist: Bordetella bronchiseptica has been transmitted to people in very rare cases, and the feline chlamydial organism has caused conjunctivitis in humans.

Can cats catch human flu?

Yes, occasionally. Cats were infected with pandemic H1N1 influenza during and after 2009, probably direct from their owners, and one such case was documented in Iowa. Illness is rare: experimental infection of cats with low-pathogenic influenza A viruses hardly ever produces symptoms, though the virus replicates for a few days.

Can you catch a cold from a cat sneeze?

No. A sneezing cat is shedding feline herpesvirus or calicivirus, neither of which infects people. Wash your hands anyway, because you can carry those viruses on your skin to another cat, and because cat discharge can carry organisms such as Chlamydia felis that occasionally do affect human eyes.

How long does a cat cold last?

Merck gives 5–10 days for milder cases and up to six weeks for severe ones. The ABCD herpesvirus guideline reports acute disease usually resolving within 10 to 14 days. Shedding lasts longer than the signs, running one to three weeks, so an apparently recovered cat can still infect others.

What temperature is a fever in a cat?

A cat's normal rectal temperature is 38.1–39.2 °C (100.5–102.5 °F), according to the Merck Veterinary Manual's reference table. In feline respiratory disease the fever may reach 40.5 °C (105 °F) before subsiding and fluctuating around 39 °C (103 °F). Anything above the normal range with lethargy warrants a call.

Should I stay away from my cat when I have COVID?

Yes, as far as your household allows. The European Advisory Board on Cat Diseases advises people with COVID-19 to avoid contact with cats and to observe good hygiene. If your cat normally goes outdoors, keep letting it out; a cat confined with a sick owner faces more exposure, not less.