Children living with a pet dog seem less likely to suffer from anxiety, a U.S. study suggests.

Research on adults who have a pet dogs suggest the companion animals are associated with better health, such as improved physical activity and mental health. But less is known about the possible relationships between pet dogs and children's health.

To that end, researchers in New York enrolled 643 children with an average age of seven at a pediatric primary care clinic when they came for their annual check-ups.

Among the 58 per cent of children with a dog in the home, 12 per cent tested positive on a screening test for potential anxiety, compared with 21 per cent of children who did not have a pet dog.

"Having a pet dog in the home was associated with a decreased probability of childhood anxiety," Dr. Anne Gadomski of the Bassett Medical Center and her co-authors wrote in Wednesday's issue of Preventing Chronic Disease.

"Future studies need to establish whether this relationship is causal, and if so, how pet dogs alleviate childhood anxiety."

So what comes first? A less anxious child is attracted to pet dogs or does the dog do all the work of relieving anxiety?

The researchers propose several ways that pet dogs could reduce anxiety, such as:

  • Stimulating conversation to alleviate social anxiety.
  • Companionship to alleviate separation anxiety and promote self-esteem.
  • Foster relaxation by leading to increased oxytocin levels, which may weaken our physiologic response to stress.
  • Provide opportunities to play, explore and increase physical activity.

But in the study, children with a pet dog and those without pet dogs did not differ in body mass index, screen time or physical activity.

Veterinarians have cautioned pets can be a source of disease-causing bacteria, especially to young children, pregnant women, seniors and those with weak immune systems.

The study was funded by the U.S. National Institute of Nursing, Eunice Kennedy Shriver National Institute of Child Health and Human Development and the Mars-WALTHAM Centre for Pet Nutrition, a division of Mars, Incorporated.

The journal is published by the U.S. Centers for Disease Control and Prevention.