The H1N1 influenza virus keeps surprising us.

Yesterday, an Iowa cat tested positive for the virus, the first time a cat has been diagnosed.

A local veterinarian says viruses are usually species-specific, unless they mutate.

"It came from other animals in the first place, came and mutated and came to us, so a lot of those viruses do mutate and spread. They do have to mutate, you can't just pick 'em up," says Dr. Karla Sathre with Wausau Animal Hospital.

Along with spreading the flu to our pets, humans can also spread parasites and bacterias.

She says the best way to prevent it, is the same way we prevent spreading the diseases to humans.

That includes practicing basic hygiene,and staying away from animals when we are sick.