But they are a disproportionate hazard for senior citizens, said CDC officials. They advise older people to improve lighting, remove pet toys and use obedience training.
"There are many benefits to pet ownership. But they also can be a hazard," said Judy Stevens, a CDC epidemiologist who co-authored the study.
Stevens, an injury researcher, said she got the idea for the study after getting asked at conferences about falls caused by pets. The report was released Thursday and is being published in the CDC's Morbidity and Mortality Weekly Report.
Researchers looked at emergency department reports for 66 U.S. hospitals for 2001 through 2006. They checked patient charts for mentions of dogs and cats involved in nonfatal injuries.
From that, they concluded that about 3 out of every 10,000 people annually suffer fall-related injuries from cats or dogs that are serious enough to send someone to the hospital.
The rate was nearly twice as high for people 75 and older. And women were two times more likely to be injured than men.
Most were quickly treated and released, but nearly 10 percent involved broken bones, internal injuries or other conditions that required hospitalization, the researchers found.
Cats mainly caused injuries by tripping people -- a phenomenon well understood by cat owners who have affectionate felines that rub against their shins and ankles during the morning walk to the coffee pot.
Dogs were blamed in most of the pet-caused injuries. They tripped people, startled them and pushed or pulled them off balance during a walk. Or they ran away and their owners toppled chasing after them. Their dog toys also caused tumbles.
"A lot of these statistics show the owner does not have complete control of dog," said Lisa Peterson, a spokeswoman for the American Kennel Club, which runs a purebred dog registry and promotes responsible dog ownership.
Obedience training can help. Also, reducing the number of dog toys and storing them each night could help. And people who might get knocked over could consider getting already-trained dogs or smaller dogs, she said.
On the Net:
The CDC report: http://www.cdc.gov/mmwr