Cat gets swine flu.

WASHINGTON (Reuters) – A cat in Iowa has tested positive for H1N1 swine flu, the first time a cat has been diagnosed with the new pandemic strain, the American Veterinary Medical Association said on Wednesday.
The 13-year-old cat apparently caught the virus from one of the people living in the house, the group said in a statement. It has recovered and does not appear to have infected anyone or anything else.
Pigs are the original source of the H1N1 virus and it has been found in several herds, as well as in a pet ferret. Ferrets are especially susceptible to human influenza viruses.
“Two of the three members of the family that owns the pet had suffered from influenza-like illness before the cat became ill,” Iowa Department of Public Health Veterinarian Dr. Ann Garvey said in a statement.
“This is not completely unexpected, as other strains of influenza have been found in cats in the past.” Both the cat and its owners have recovered from their illnesses.

From a reader:

Bugs that go interspecies have more variants, higher mutation rates, or both. Which means this particular virus might readily go from the makes-you-miserable-for-two-weeks to the kills-millions-outright version faster than we can adapt.