Want to hear something funny – one of the top three words a new baby says is “dog” or that child’s specific family dog’s name. It’s right up there with “uh-oh, dada, mama and no”! And why is that – because often dogs are licking baby’s face, enthusiastically finishing off the “yucky” food toddlers toss to the ground, making strange sounds, running around wildly, and of course, just being ever present. And how does the family pet’s presence affect a newborn, toddler or child?

There was a time when people believed that being exposed to a pet would increase a child’s risk of pet allergies. Conventional wisdom in the recent past was if allergies of any kind ran in your family, it was best to raise your children in a pet-free home. However, this approach couldn’t be further from the truth… Children raised around furry creatures, whether it be a dog, cat, sheep or horse are less likely to suffer allergies, eczema and asthma, and in some studies are noted to have a more robust immune response to infection-causing bacteria.

An interesting parallel to this idea, recently described in the Wall Street Journal, compared babies whose parents had “cleaned” a dropped or dirty pacifier in their own mouths before reinserting the binky, with babies whose parents had never engaged in such an approach. The article discussed how much dirtier the pacifier became after entering a parents mouth and how most of us had erroneously assumed this would make a child sick. In fact, the babies exposed to this constant, albeit low grade onslaught of bacteria from their parent’s mouths, had fewer allergies and infections when compared to the control children. Whether it’s bacteria from the ground or a parent’s mouth, or the bacteria pooling in your lab’s mouth, some exposure primes the immune system without being of substantial enough quantity to actually cause acute illness. If your immune system rarely sees that which it should mark as foreign and pathogenic, what should it react to? In my reasoning, allergy runs parallel to autoimmune disease – the highly complex and elaborate immune system is basically misfiring. What should the immune system fear if it has never seen the face of the enemy?

If your immune system rarely sees that which it should mark as foreign and pathogenic, what should it react to?

So, the moral of the story – let the dog lick your babies face here and there, a little ingested dirt is no big deal, a pacifier doesn’t necessarily have to be sterilized just because it fell on the floor—I guess there is some merit after all to the 5-second rule.