ATLANTA, Nov. 30 (UPI) -- Pet dogs are well-known to be beneficial to adult physical and mental health because they encourage people to exercise and increase social interaction. A new study, funded by the Centers for Disease Control and Prevention, shows dogs may also reduce the risk for childhood anxiety.
Previous studies have shown dogs can reduce the risk for allergies and asthma in children, improving children's immune systems by exposing them to allergens early in life.
The researchers said the cycle of play, caretaking, social interaction, and companionship has preventive benefits because anxiety and obesity often are rooted in childhood.
"There is a very strong bond between children and their pets," Dr. Anne Gadomski, a researcher at Bassett Medical Center, told NBC News.
The researchers enrolled 643 children between the ages of 4 and 10 at a not-for-profit pediatric clinic in upstate New York between July 2012 and December 2013, surveying their parents before and after their children's annual check-up.
Using a Web-based screening system called DartScreen, the researchers collected age, sex, height and weight information measured by nurses. Only one child per family could participate, and the researchers excluded ill or developmentally disabled children from the survey.
The survey included questions about somatic and mental health, nutrition, physical activity, parental depression, and whether or not the child has difficulties with emotions, attention, behavior or social interaction. At the end of the survey, parents were asked if a pet lived with the family. If the answer was yes, and dog was selected as the pet, more questions were asked about how long the child had been exposed to the dog, physical activity with it, and how much time the child spent with the animal.
Based on completed survey information, the researchers determined that 57.5 percent of children had a pet dog, compared to 42.5 percent without one. No significant difference in BMI, screen time or physical activity between children with and without pet dogs.
Using the Screen for Child Anxiety and Related Disorders to measure levels of anxiety, researchers found 21 percent of children without pet dogs scored above a 3, meaning further assessment was indicated to diagnose anxiety. Only 12 percent of children with dogs had a score of 3 or higher on the survey.
The researchers speculate dogs could reduce childhood anxiety by stimulating conversation with other people, easing separation anxiety because of the animal's companionship, and increased oxytocin levels that reduce cortisol, the physiological responses to stress.
Despite survey data, the study is limited by not showing a causality, researchers wrote in the study. To get a better picture, future research will need to involve families who get a dog and are followed for a long period of time and are compared to a group that does not have a dogs.
"Because this was a cross-sectional study of associations, a correlational study, no cause or effect can be inferred," researchers wrote in the study, published in the journal Preventing Chronic Disease. "It may be that less anxious children have pet dogs or pet dogs make children less anxious."