Derek Speirs for The New York Times House cats like these appear to be vulnerable to catching flu from humans.A few days after two members of an Ames, Iowa, family came down with the flu, they noticed their 13-year-old cat wasn’t feeling too well either. The cat has since become the first documented case of a feline with the new H1N1 virus, commonly called swine flu.
The unusual case has riveted pet owners and health officials. Companion animals have been known to contract flu from other species — canine influenza (H3N8) originated in horses, and cats contract avian influenza (H5N1) from eating birds. But this appears to be the first time a cat has contracted influenza from a human. Two pet ferrets, one in Oregon and one in Nebraska, have also tested positive for H1N1, and the virus has also been transmitted between humans and pigs.
The cat was treated at the College of Veterinary Medicine at Iowa State University by veterinarians Dr. Brett A. Sponseller and Dr. Albert Jergens. Although the family has asked not to be identified, Drs. Sponseller and Jergens have disclosed additional details about the case.
The cat, a 16-pound orange tabby, began acting lethargic and lost his appetite on Oct. 27. He is the only pet in the house and never goes outside. The cat, described as “large framed but not chubby,” stopped eating and drinking and stopped cleaning himself. He also rested by hunching on all four feet, rather than sprawling out on his side as usual, a sign of respiratory discomfort. A few days earlier, two out of three family members in the home had developed flu-like symptoms, with fever and body aches.
The worried pet owner called Dr. Sponseller, a specialist in large animal internal medicine and molecular virology, who happened to be a family friend. At the time, neither Dr. Sponseller nor the pet owner suspected the flu — because the cat had vomited, they wondered whether he might have a gastrointestinal problem.
The next day, the cat arrived at the veterinary school, where he was seen by Dr. Jergens, a small animal specialist and immunologist. Upon examination, it appeared the cat had a respiratory condition, so Dr. Jergens performed a bronchial lavage, injecting fluid in and out of the lungs to collect cells to determine what was making the animal sick.
“It didn’t reveal anything that was consistent with what we typically see with pneumonia in a cat,” Dr. Sponseller said.
Although cats can contract flu from birds, this cat never left the house and was never exposed to any other pet. At that point, it occurred to the veterinarians that since the family members had been recently ill, they might be seeing a case of flu transmitted from human to cat. The school is the site of a major diagnostic lab, so the veterinarians were able to test the cat and quickly confirm he had H1N1, a finding that was later confirmed by additional testing by the U.S. Department of Agriculture.
Additional testing is being conducted to confirm that the family members had H1N1 and to try to verify that the flu was transmitted from human to cat. However, the circumstantial evidence is strong that the cat was infected by its owners and not the other way around. “This cat does not go outside,” Dr. Sponseller said. “Whatever came in, came to the cat.”
Dr. Sponseller says the cat is about 85 percent recovered. He was given fluids for dehydration and put on antibiotics to prevent a secondary bacterial infection. “He’s eating well, moving around well, and he’s back in his window watching the squirrels outside,” he said.
While the Iowa tabby is the first documented case of H1N1 in a cat, it’s possible that other cats who haven’t been tested also have contracted the virus from pet owners. “Since this news story broke, I’ve had owners from around the country sending me e-mails about their experiences,” Dr. Sponseller said. “It’s suggestive that it has happened before, but there’s no confirmation.”
Dr. Sponseller said there is no evidence that a cat could give a person the flu, and transmission is unlikely because cats with flu typically don’t cough or sneeze.
It’s not clear how the cat contracted the virus, but given how easily flu is transmitted between family members, it’s not particularly surprising that a friendly cat would come into contact with the virus as well.
“He’s a very social cat,” Dr. Sponseller said. “He would visit with them in their laps when they were watching television or reading. He was known to climb up on the bed. He’s a very charming cat with a lot of personality.”
To hear more about protecting your pets from flu, read “Can Pets Get Swine Flu?” and “10 Things to Know about the H3N8 Dog Flu,” on the Consults blog.
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From 1 to 25 of 47 Comments
It’s possible for the flu to jump species, and that it has many times - but it’s still very rare. Are there never any false positives with the H1N1 test? The circumstancial evidence is pretty convincing here, but I’m waiting for the confirmation tests.
FROM TPP — This cat definitely had H1N1 (several tests have confirmed) and it only has contact with humans. Still, gene sequencing will prove it beyond a doubt — and those tests are forthcoming.
— AllieTPP - thanks for clearing that up!
— AllieSo would the vaccine that humans are getting against swine flu work to protect pets too? I’m sure there will never be enough of it made, though, since humans are facing a shortage already……..
— bgCan cats catch colds from their humans too? When my husband or I get a cold we try to be careful about spreading it to each other, but I never worried about my cats catching it from me.
— AuraleeTPP, would you please follow up to see if the family members were positive for H1N1? If they are not, then it is nearly impossible to believe that the cat really had it, especially if there turns out to be no viral DNA from the cat’s lungs. Please follow up on that, too. Antibody tests, especially on animals, can be falsely positive.
You might reply that an visitor to the house could have given to the cat, but then why were the family members spared (if they test negative)?
FROM TPP — Why is it impossible to believe the cat had it, if several flu tests confirmed it? And there was evidence of a viral infection from the lungs. The family had flu-like symptoms, and the researchers are following up with additional tests to confirm H1N1 in the family members, but given that 99 percent of the flu circulating is H1N1, I think the evidence here is strong.
— jackI’m not too surprised that a cat could catch the swine flu if it’s going around the family. They say that dogs and owners often share a physical resemblance (something I’ve noticed around the dog park, myself) but I think it’s uncanny how our pets so often reflect the health of their owners, as well. Has anyone else noticed this phenomenon?
— MelissaThis is helpful to know. My fiance and I both got vaccinated for both H1N1 and seasonal so we’re fine, but now I will be extra careful to wash my hands when I come home before I play with the cat.
— LS#5TPP response:
It is hard to believe because human to cat transmission has never been documented before.
You say the cat had a viral infection, but there are many cat viruses that can infect the lung.
The family had “flu-like” symptoms, but this could be anything from a bad common cold to a bronchitis caused by a coronavirus.
The evidence is currently suggestive. I would say that the evidence is not strong until they confirm that the family members had H1N1. It would be airtight if the cat’s lungs had H1N1 DNA.
So, good reporter as you are, I’m sure you’ll be following up with us on this!
FROM TPP — I asked Dr. Sponseller to respond to your question. Here is his reply.
“Your reader has posed two distinctly different questions. First, did the cat have H1N1 pandemic Influenza? The bronchial lavage sample was submitted for cytologic evaluation and nucleic acid testing for influenza. The cytologic evaluation ruled down many common causes for acute respiratory distress in the cat and was consistent with a viral cause. Screening and typing PCR tests performed at Iowa State University were positive, with the typing tests positive for H1N1. Extramural testing at USDA was also positive for H1N1. We concluded that the cat was infected with pandemic H1N1 influenza.
Secondly, did the cat get H1N1 Influenza from the owners? Your reader is correct that this transmission event (human to cat) is presumptive at this time. This is a single cat household and an indoor only cat; there are no other pets. So, circumstantial evidence indicates that the source of the influenza virus was an infected human. Retrospective testing of the owners is underway to close the loop.” — Brett A. Sponseller, D.V.M., Ph.D.
— jackI guess I’d better stop letting my little companion lick from my cereal bowl. I don’t want him to get sick.
— a.Poor old moggy! Human to cat transmission does sound odd.
so what does cause cats to sneeze and cough? Our cat had a horrible upper respiratory tract infection when we adopted her from the shelter (they offered to put her down and let us choose a different one but we didn’t think she should lose her life because she caught a cold) and she was sneezing for a week.
FROM TPP — Other upper respiratory viruses/infections can cause a cat to sneeze and cough. But with flu, it tends to affect the lower respiratory tract, according to the vets I spoke with.
— TessaMy mom used to save back meds for the cats when we kids were sick. She said they very often seemed to get whatever we had. I suspect it happens more than is “proven”. People just don’t take the cats in before they improve OR the vets just give antibiotics against secondary infection without testing, since, who tests for flu strains in cats? You just follow a common sense protocol like that.
— Karen CI wonder if Tamiflu (oseltamivir) would help cats and if it would be safe for them. I guess the dose would have to be adjusted.
— rini10While what I have to say is anecdotal, it does pertain to this report of trans viral infection between a family and it’s cat.
There was a point last spring when H1N1 was going through Ohio, and my husband I both came down with what I believe was the H1N1 flu. We had the classic symptoms, with both of us rapidly progressing into secondary respiratory infections. We did not get tested - just not enough interest at that point to do so.
About 4 - 5 days into our flu cycle, I noticed our 2 cats were both not eating, throwing up and sneezing & coughing (!). They felt warm to the touch and were not happy—this lasted about 5 days.
Of course, the story begs the question - did it go from human to cat, or vice versa? Or were the cats thinking our sneezes and coughs were some kind of communication they wanted to mimic?
— Janet BertinotI had the “normal flu” a few weeks ago and my faithful companion Holly (a tuxedo cat) caught a cold. She sneezed, threw up, loss of appetite and slept as much as she possibly could. She actually took over my heating pad. She is also a house cat - never outside.
I didn’t realize it was unusual for house pets not to catch what their owner have because we have seen it several time throughout the years.
I am so glad this little kitty is getting better. She is so cute!
— KCThis was the very first time I have ever heard such kind of news :) I never thought that this could even be so possible :( That is so sad to hear that even your beloved cat can get the H1N1 virus :(
— kayacamillaTara, I think your response to your reader comments is extremely impressive. I can’t recall a Times reporter going back to their source like that from reader comments.
FROM TPP — Thanks for the kind words. What I like so much about online journalism is that it does give you the opportunity to tap into the knowledge of readers and offer additional information in a timely manner.
— SethI just brought my 5yr old cat into the vet. nov. 3rd cause he was really lethargic an not eating an drinking much an he was very warm to the touch….
— DanielleThe odd thing about my cat is that he’s been like this on an off since aug. of this yr.
The vet only did the basic blood work which there were three areas of high readings….
The vet was unsure of what it could be so they put my cat on vet viralys gel 2 times a day….
but this is day 3 an my cat is still lethargic and very hot to the touch still hes not eating an drinking well….
An yes we have all been sick with the flu …
My cat is an indoor cat only an i do have another cat in the household an she has been under the weather to ….
The vet that I go to is:
Memorial Drive Veterinary Clinic,Inc.
1415 Memorial Drive
Manitowoc ,Wis.54220
920-682-6558
Came you please help my cat I feel so bad for him he’s sick an I dont want to loose the little guy over a stupid flu bug…
I thought I’d heard months ago, when we first learned of the H1N1 outbreak in Mexico, and earlier, when there was an outbreak of avian flu in Asia and Canada, that viral infection between species required/indicated a mutation in the virus. Also, that the more frequently the virus mutated, evidenced by the number of species infected (humans, cats and ferrets, presently), the more virulent the virus, or at least the harder it is to defend against. Is this true?
— LaniSome bloggers and people on pet forums have noticed that this infection occurred not long after the live nasal vaccine for pandemic H1N1 flu was distributed in Iowa.
http://thedailybite.wordpress.com/2009/11/05/h1n1-swine-flu-found-in-iowa-cat-human-nasal-vaccine-link/
This is an engineered strain comprised of 2 genes from the wild virus and the other 6 are derived from a proprietary master virus to give it the attenuated characteristics.
The timing along with the fact that the US is the only country using that vaccine makes me wonder if it was tested as far as being transmissible to household pets.
— DanforthWhat are the implications? Are our pets in danger?
— MamakangarooFROM TPP — I don’t think we know the implications yet. This virus is full of surprises and the ability to jump to a new species is one of them. We just don’t have enough information to fully grasp what it means for humans, cats or the virus itself.
Poor kitty! :( I’m glad he is making a recovery. I’m with a., if I’m sick I’ll have to stop sharing my cereal milk with my cat Lovey!
— EmilyTPP, great followup. Given the H1N1 DNA in the cat’s lung, and the case history, the cat had to have gotten the flu from humans. It was crucial to know the DNA data, since antibody tests can be falsely positive.
This is potentially very significant, for now, this H1N1 strain has shown the ability to jump multiple species. Let’s hope it does not mutate into something that cats can give back to humans!
FROM TPP — Dr. Sponseller gave me this additional information you might find interesting:
Here is more information regarding samples where virus was isolated from the sample. In the case of the cat treated at Iowa State University, a small aliquot of the bronchoalveolar lavage sample was injected into chicken eggs and virus grew. This work was performed at the USDA as reported below.
http://www.usda.gov/documents/FINAL_RESULTS_2009_PANDEMIC_H1N1_INFLUENZA_CHT.pdf
— jackRe: #10
The shelter may have had good reason for recommending you not adopt your kitty - sneezing (with a lot of mucus) is frequently caused by Feline viral rhinotracheitis (FVR - or cat herpes). It’s a chronic condition common in shelters, highly transmittable to other pets, and not completely preventable.
I learned this the hard way - one of my kitties, Zelda, was diagnosed shortly after adoption. She was very loving and positively adorable, except the way she would wipe snot on me… and the walls… and the couch… and the dog… for months at a time! She was finally adopted to a single-pet family, as my other animals were at risk and I couldn’t afford the constant antivirals.
— Laura, RNTo jack #5, #8, #22:
All influenza viruses, including 2009 H1N1, are RNA viruses. They don’t have DNA.
— LEMThe virology behind a human giving the flu to a cat makes sense. There are several different kinds of sialiac acid receptors some of which are species specific. Most mutations in the flu virus that allow the virus to jump species involve sialiac acid receptors. Flu viruses enter the cells in human lower respiratory tract (aka the lungs) using sialic acid receptors with a 2,6 linkage. Cats have the same receptors in their lungs, so the virus has the potential to infect cells in feline lungs. These same receptors are also present in pig lungs. The level of different receptors is related to virulence of the virus, which explains why it is harder for the cat to become infected. But with a high enough dose virus, I’m not surprised that the kitty got sick.
— Virology PhD student