Study finds dogs, cats help babies’ health

LOS ANGELES – Fido the dog and Ginger the cat need not worry about being replaced by a new baby – in fact, they could be helping parents raise healthier children.

A new study finds that children who lived with dogs or cats during their first year of life got sick less frequently than kids from pet-free zones. The study, published in Monday’s edition of the journal Pediatrics, provides fresh evidence for the counterintuitive notion that an overly clean environment may not be ideal for babies.

Sharing a home with a pet may be an early form of cross-training for the body’s defense systems. Previous research has shown that owning a cat or dog was associated with less risk of gastroenteritis in young children. Studies also suggest that the dirt – and microbes – brought indoors by pets could bolster the communities of helpful bacteria, yeast and other microscopic creatures that live in a developing child’s body.

For the new study, European researchers tracked the health of 397 Finnish children born between September 2002 and May 2005. When the infants were 9 weeks old, parents began keeping weekly diaries to document a number of indicators of their children’s health, including runny noses, coughs and ear infections. Parents also noted when their babies were given antibiotics. When the children celebrated their first birthdays, the parents were asked to complete a questionnaire.

Overall, the researchers found that cats and dogs were linked to a reduced incidence of various types of illness. The effect was stronger for dogs than for cats: Babies who lived with dogs were 31 percent more likely to be in good health than their counterparts who didn’t, while babies with cats had a 6 percent advantage over those without feline family members.

The children with pet dogs were 44 percent less likely to develop ear infections and 29 percent less likely to have used antibiotics during their first year, the report said.

Here’s where the plot thickened: Although living with a cat or dog was correlated with good health, the benefit was biggest when those pets weren’t around the house very much.

The researchers offered a possible explanation for the puzzling pattern: Pets that spent more time outdoors brought more dirt into their homes, giving babies more opportunities to encounter it. That exposure could have caused their immune systems to mature faster than they would have otherwise, they wrote.