Cats and Babies
Many people think that it's not a good idea for small children and pets to live together under the same roof (especially when it comes to pets who shed as much hair as cats do). Some worry that putting their children in contact with animal dander may cause them to develop allergies or asthma later on.
However, a recent Danish study found that the opposite was true: exposure to cats can actually prevent asthma in newborns. Exposure to dogs, on the other, did not appear to have any effect on the children's odds of developing asthma later on in life.