A dog could be a baby's best friend, according to a study in the medicaljournal Pediatrics.

Infants living in households with dogs were healthier and had fewer ear infections than those without a dog, the study found. Researchers also found that cats appeared to offer some protection, but the link wasn't as strong.

The study, posted online Monday and based on 397 children who lived in rural and suburban parts of Finland, examined whether contact with dogs and cats during a baby's first year offers any protection from respiratory tract infections, such as colds and resulting common ear infections. 'The children having dogs at home were healthier, they had less ear infections and they needed less antibiotics,' said Eija Bergroth, the study's lead author and a pediatrician affiliated with Kuopio University Hospital in Kuopio, Finland.

One measure showed children with dogs were reported as being healthy for about 73% of the time, based on weekly questionnaires, compared with about 65% of children with no dog contact at home. While the study tracked just under 400 babies, the researchers said the results were statistically significant because it relied on weekly questionnaires filled out by parents.

Dr. Bergroth explained that children who lived in households where dogs spent 18 or more hours a day outside, showed the most healthy days, fewer fevers and the least use of antibiotics compared with babies with no dog at home. One theory is dogs that spend a lot of time outside likely bring more dirt and bacteria inside the home compared with dogs and cats that spend more time indoors, she said. Researchers believe that exposure to dirt and bacteria builds up babies' immune systems.

Researchers found that 97% of babies