The pandemic flu bug was detected in a sick, 13-year-old Iowa cat after two members of the family that owns the cat fell ill, the Iowa Department of Health reported yesterday.
The cat -- and both humans -- recovered from their illnesses.
"It's not unexpected news ... we know that influenza viruses can be transmitted between humans and animals," CDC spokesman Tom Skinner tells WebMD.
The Iowa cat was taken to the veterinary college at Iowa State University, where tests of a nasal swab confirmed the cat was infected with the H1N1 swine flu virus.
"Just because the virus was found in a sick cat doesn't mean the virus was the cause of the cat's illness," Atlanta veterinarian Megan Hilf, VMD, tells WebMD.
Even so, the CDC warns people with flu-like symptoms to avoid giving the virus to their best friends.
"If people are sick and have pets and they are concerned, then we suggest they follow the same steps we tell them to follow when it comes to preventing spread to other humans: Cover coughs and sneezes, frequently wash your hands, and try to distance yourself from your pet until you have been without fever for 24 hours without use of fever-reducing medicine," Skinner says.
Can cats carry H1N1 swine flu and transmit it to people or to other pets? Maybe, says Drew Weigner, DVM, a feline specialist in Atlanta.
"There is currently no evidence that cats can transmit H1N1 to people," Weigner tells WebMD. "While there is currently no evidence that cats can transmit H1N1 to cats or other pets, it would not be surprising to find transmission from one cat to another -- but this is not yet known to have occurred."
Cats do readily become infected with another worrisome flu bug -- the deadly H5N1 bird flu. Fortunately, that killer virus has not become widespread in either cats or humans. And the H5N1 virus is very different from the H1N1 swine flu virus.
In fact, Weigner says, cats rarely get infected with any kind of flu virus.
"What is often referred to as 'cat flu' is actually a syndrome describing an upper respiratory infection with several different viruses such as herpesvirus and calicivirus," he says.
A 2007 study of blood samples collected from 1999 to 2005 from 60 domestic and 51 free-roaming cats in and around Milan, Italy, showed no indication that any of the animals had ever been infected with any flu virus.
But if a cat does get a human flu bug, what symptoms would it have?
"Since only one cat has been confirmed to be infected with H1N1, it remains to be seen how this virus affects cats," Weigner says. "One would expect infected cats to have a fever and upper respiratory symptoms including sneezing and eye or nasal discharge. The most important point is that any cat exhibiting signs of illness should be examined by your veterinarian as soon as possible."
Weigner and Skinner note that other animals have picked up H1N1 swine flu from humans, including pigs, birds, and ferrets. H1N1 swine flu is a human virus not known to be circulating in pigs.
The diagnosis of swine flu infection in the Iowa cat was a collaboration between the Iowa Department of Public Health; Iowa State University College of Veterinary Medicine; the Center for Advanced Host Defenses, Immunobiotics, and Translational Comparative Medicine, the U.S. Department of Agriculture; and the Iowa Department of Agriculture and Lands Stewardship Animal Industry Bureau.