ALBUQUERQUE—The foot-long Tokay gecko's polka-dot skin and wide eyes have made it popular with pet stores, where it can sell for less than $20. But the adorable Asian lizards are also a mixing pot for 10 types of salmonella from local livestock, poultry and rodents, a researcher said today.

For the last several years, Katherine Smith at Brown University and colleagues have worked to document the pet trade's potential to bring new and dangerous diseases to the United States. As Smith reported in Science earlier this year, the U.S. imported 1.5 billion live animals between 2000 and 2006, just 14 percent of which have been identified to species in government records. Even less well-known are the pathogens they may contain. In 2003, for instance, a Gambian pouched rat started an outbreak of monkeypox in the Midwest.

At the Ecological Society of America meeting here today, Smith described new results from a study of 150 wild-caught Tokay geckos imported from Indonesia. She found that 60 percent of the geckos tested positive for Salmonella, which was not too surprising considering that 10 percent of salmonella cases are caused by reptile pets, such as slider turtles and iguanas.

We knew they could bite, scratch or make us sneeze, but Fido and Fluffy may be hazardous to our health for another reason: they can cause us to fall. America's dogs and cats, it turns out, can be blamed for injuries caused in an estimated 86,000 falls treated each year in the country's emergency rooms, federal health officials said today.

Nearly 88 percent of those injuries come at the paws of man's best friend, who's more apt to wound the fairer sex, epidemiologists report in today's Morbidity and Mortality Weekly Report (MMWR). About a quarter of those spills occur when a pet owner is walking his or her dog, and twice as many women as men are hurt.  

"Most people think of pets in terms of tripping over them. They don’t think of walking a dog as a hazard," Judy Stevens, an epidemiologist in the U.S. Centers for Disease Control and Prevention's (CDC) injury center, tells ScientificAmerican.com. Dogs, she adds, are more likely to be dangerous than cats because "they tend to be bigger and stronger and you have to walk them, which you don’t with cats." Women, she says, are more likely than men to take a tumble if a pup pulls during a stroll, because they generally weigh less and aren't as strong.

Some 79 people in 21 states have been sickened with a bacterial infection linked to contaminated pet food — the first time human Salmonella enterica illness has been traced to a contaminated animal food plant.

None of the cases were fatal, and no pets became ill, according to this week's Morbidity and Mortality Weekly Report.

The manufacturer of the dry dog and cat chow food linked to the outbreak, Mars Petcare US, recalled the 105 products in September and closed its Everson, Pa., factory where the tainted kibble was made, Centers for Disease Control and Prevention (CDC) scientists say. But they warn that some of the food may still be on consumers' shelves and shouldn't be fed to pets. Among the tainted brands: Pedigree, Country Acres, 'Ol Roy and Paws & Claws.