The study published in Pediatrics
tracked 397 infants in rural Finland, France, Germany, Austria and Switzerland from the third trimester of pregnancy until they turned a year old. Parents filled out weekly diaries asking about their child's health and whether they owned a pet.
The study discovered that babies who had early contact with dogs or cats were significantly healthier during the study and were almost a third less likely to experience coughs, a stuffy nose, sneezing and congestion. Babies born in homes with dogs were also 44% less likely to develop ear infections, a very common childhood ailment. They were also 29% less likely to have used antibiotics during their first year than infants without pets. The rates for infants in homes with cats were also better but less than in homes with dogs.
The study results lead researchers to believe that early contact with an animal may help mature the immune system in infancy, helping children to better fight off common childhood illnesses. One of the study's authors, Dr. Eija Bergroth a pediatrician in Finland, wrote
"Our findings support the theory that during the first year of life, animal contacts are important, possibly leading to better resistance to infectious respiratory illnesses during childhood."
The strongest benefit was seen in children who had a dog that was inside for 6 hours a day or less rather than all day. Dr. Bergroth tells WebMD
"it might have something to do with dirt brought inside by the dogs, especially since the strongest protective effect was seen in children living in houses where dogs spent a lot of time outside."
The so-called Hygiene Hypothesis
suggests children's immune systems mature best when infants are exposed to germs in just the right amount. Too many germs are unhealthy but so is a sterile, germ-free home. Dr. Karen Demuth, associate professor of pediatrics at Atlanta's Emory University tells WebMD
that every child is different.
"Certain people who have a dog in the house are protected against infections and allergies but some are not. This is not a one-size-fits-all kind of thing."
It's also interesting to note that not everyone kept their pet throughout the study. While 62% had a dog in the house and 34% had a cat at the start of the study, by the end of the year only 35% of homes still had a dog and 24% still had a cat.
So does this mean expectant parents should run out and get a dog? Dr Jennifer Appleyard, chief of allergy and immunology at Detroit's St. John's Hospital tells HealthDay
"I think the development of the immune system is very complicated. Parents shouldn't feel guilty about having or not having a pet when their child is young. If you want a pet, get a pet."
And Dr. Demuth adds,
"The absolute worst thing is to put a dog in a house for kids with asthma. Yes having a dog in the house can protect against wheezing or respiratory infection, but this exposure has to happen early in life."