Katy Nelson, a veterinarian from Alexandria, Va., feels fortunate that her young children -- a 4-year-old son and 1-year-old daughter -- haven't been sick very much.
"My daughter had one cold after she turned 1," Nelson said.
She attributes their good health to a number of things. She keeps a clean house, washes her children's hands and has pets -- a dog and a turtle.
"Science has proven having pets can have multiple benefits, both psychological and medical," she said.
A new study published in the journal Pediatrics suggests that she may be right about the health benefits of pets.
Finnish researchers found that having dogs or cats during infancy may actually protect children from respiratory illnesses during the first year of life.
They followed 397 children from the time their mothers were pregnant through age 1. They found that those who were exposed to dogs at home had fewer respiratory illnesses or symptoms compared with children who didn't have dogs. Children with dogs also had less-frequent ear infections and needed antibiotics less often than children never exposed to dogs. Cats offered similar protective benefits, but to a lesser degree.
The findings, wrote the authors, suggest that early contact with dogs or cats may ramp up infants' immune systems.
"We speculate that animal contacts could help to mature the immunologic system, leading to more composed immunologic response and shorter duration of infections," they wrote.
The amount of time a dog spends inside the home also has an impact on children's respiratory health. Children who live in houses where dogs are inside less than six hours a day are at lowest risk for respiratory problems. The authors believe it could be because dogs that are inside track less dirt. More exposure to dirt leads to more exposure to different types of bacteria, which can help strengthen the immune system.
Other studies also suggest that pets can lower children's risk of certain illnesses. Research out of the University of California, San Francisco published in June found that dust in homes where there are dogs may protect children against respiratory syncytial virus, a common cause of potentially severe cold-like illnesses.
And Nelson pointed out other research.
"One study found that children who grow up on farms and ranches have stronger immune systems later in life," she said.
May Be Dangerous for Children With Allergies
But the Finnish study didn't include parents with allergies to dogs or cats. Parents with these allergies are more likely to have children with the same allergies, and having pets around very young children who are allergic may be unsafe.
"If an infant has an allergic predisposition, their reaction will be more pronounced than an older child's," said Dr. Nina Shapiro, director of pediatric otolaryngology at UCLA's Mattel Children's Hospital, meaning that if an allergic infant is exposed to a dog or cat, it can potentially be dangerous.
That's what kept David Bakke from getting a pet for his son, even though the little boy always wanted one. Bakke, an editor at Money Crashers Personal Finance, is allegic to several animals.
"We decided against it because of potential health risks for myself as well as the possibility of long-term respiratory illness for my son," Bakke said.
Concern over both vet bills and medical bills for any pet-induced human illnesses also played into his decision.
If it weren't for his allergies and the risk to his son, Bakke said knowing more about the research out there on pets could make him change his mind.
"Not only could he gain from the social benefits of owning a pet, but there would be major health benefits as well."
It's those social benefits that experts say can also be protective for non-allergic pet owners and their families. Pet owners can attest to the happiness and humor animals can bring into their lives, and it's exactly those emotional benefits that contribute to physical health as well.
"There are families with pets that may gain some comfort from having pets, which may breed a healthier environment," said Shapiro, also the author of "Take a Deep Breath." "Stress is associated with illness. There may be the intangible effects of easing stress, and it may be the relief of stress that is could be a factor."
"There's no way to separate pets and kids in your life, especially if the pets came first," Nelson added. "If we keep our pets clean and parasite-free, keep our houses as clean as we can and wash our kids' hands, we don't have to be afraid of bringing pets into our household."