Forget swine flu – meet Fido flu

Recent news reports claim that a domestic cat had come down with H1N1 swine flu, probably transmitted to the feline by sick owners – making many people wondered how vulnerable their own pets were to the illness.

So, does Fluffy or Fido need protecting from this strain of flu? The answer, experts say, is basically no.

While the H1N1 flu currently circulating can jump easily from person to person, it does not travel well from humans to animals or animals to humans, except in a few rare instances.

Not impossible
"This really is not a practical issue at this point," said Dr Chris Olsen, a professor of public health and associate dean for academic affairs at the University of Wisconsin School of Veterinary Medicine in the US. "Is that to say it's not possible? No."

And even when inter-species transmissions do occur, the H1N1 virus seems more likely to move from humans to animals, rather than the other way around.

The Associated Press reported that veterinarians at Iowa State University College of Veterinary Medicine announced the first laboratory-confirmed case of H1N1 infection in a cat. Veterinarian Dr Brett Sponseller said two of three people who lived in the house with the 13-year-old feline had shown flu-like symptoms before the animal became ill. The cat was treated and has since recovered, the AP said.

Olsen said there have also been reports of the virus crossing from humans to livestock - in particular pigs and turkeys, and mostly in agricultural settings.

People infect animals
There have been instances "where the current pandemic virus has been isolated from pigs [the first identified at the Minnesota state fair in August], and [some] instances from turkeys. But, in all of those cases, it's quite clear that the person was the source of infection for the animals, not the other way around," Olsen said.

Several cases of pig-to-human and human-to-pig transmission of the seasonal flu have been documented but it's mostly in agricultural settings, added Dr John Treanor, director of the infectious diseases division at the University of Rochester Medical Centre in New York.

In fact, the US Department of Agriculture said that it had detected H1N1 in a commercial herd of pigs in Indiana, the AP reported. Again, both the pigs and the humans caring for them recovered from the flu, the news agency said.

Biosecurity precautions
According to Olsen, the livestock industry already has elaborate biosecurity precautions in place - everything from asking about workers' health, to protective clothing, to having employees shower before entering or leaving a facility.

Although it's called the swine flu, the H1N1 virus is no longer really a pig virus. "This has been a human-adapted virus since we first recognised it in the early spring of this year," Olsen said, adding, "You absolutely cannot get it from what you eat."

No precaution needed for pets
And dog and cat owners don't need to take any extra precautions when it comes to the H1N1 flu, even though there have been instances of animals contracting, and sometimes even passing on, the regular seasonal flu.

Ferrets, for instance, are generally susceptible to the seasonal flu, and the AP reported that H1N1 infection has been confirmed in two ferrets, one in Nebraska and the other in Oregon.

"Not only can they be infected with the flu, but they are clearly able to transmit the flu back to people," Treanor said. "This is how flu viruses were first discovered. They [researchers] were looking at what the cause of flu would be, back in England in the 1930s, and noticed when they infected ferrets with material from the flu lab, workers got the flu from the ferrets. That led to the discovery of the influenza as the cause of flu."

Dogs and flu
Olsen added: "There are also reports of the human influenza virus going from people to dogs but this is, again, a rare occurrence."

Dogs can get something called the canine influenza virus, but that "has adapted itself to dogs and really is a dog pathogen at this point," Olsen said. It originally came from horses, and mainly affects canines in an animal shelter.

Similarly, a recently developed dog flu vaccine has nothing to do with H1N1, said Dr Bonnie Beaver, a professor in the department of small animal clinical sciences at the Texas A&M University College of Veterinary Medicine & Biomedical Sciences. "It's for a totally separate disease. It's not something people get."

"Our concern is transmission from human-to-human but we do need to protect pigs [and turkeys]," she said.

"Each animal tends to get its own kind of flu," Treanor said. - (Amanda Gardner/HealthDay News, November 2009)

Read more:
Swine flu map
Swine flu timeline