I just read a very interesting article in "Catnip", the newsletter for cat owners published by Cummings School of Veterinary Medicine at Tufts University. The article was based on a study indicating that infants who lived with cats or dogs during their first year of life got sick less often than children without pets. Experts believe that sharing your home with a pet is like a cross-training for the infants immunity system, bolstering its ability to fight off disease.
The European study followed 307 Finnish children between the ages of nine weeks and one year. What they discovered was that babies who lived with dogs were 31% more likely to be in good health than those who did not; and those babies that shared their home with cats had a 6% advantage over those without felines.
This is great information for new or expectant parents who are concerned that having a pet around their new baby could be a bad thing.