Putting a dog with a baby can do more than just provide good entertainment. (Puppies vs. Babies anyone?) A new study reported in Los Angeles Times found that children who live with pets were on a whole healthier than those that did not. 

The study, conducted by European researchers and published today in the journal Pediatrics,  looked at 397 children born between September 2002 and May 2005 in Finland from nine weeks to a year old and had their parents record any signs of being sick: runny noses, coughs, ear infections, admistering antibiotics, and the like. When they compared that to whether any pets were in the house, they found that babies living with dogs were 31 percent more likely to be healthy than those in a dog-free household; kids with cats were 6 percent more likely to be healthy over the cat-less.  

The reason this was the case, however, may not be terribly persuasive to pet-less parents. Those animals are filthy, or at least filthy enough to track in all sorts of germs that help babies develop stronger immune systems. As the L.A. Times explains, "Pets that spent more time outdoors brought more dirt into their homes, giving babies more opportunities to encounter it. That exposure could have caused their immune systems to mature faster than they would have otherwise."

And in another wrinkle, while pets were linked with healthier babies, the less time the animals spent with them the better: babies at homes with cats who are only allowed in the house for six hours a day or less were healthy 78 percent of the time, while those with cats indoors more than 16 hours a day were healthy 71 percent of the time and cat-free homes had babies healthy 66 percent of the time. There was a similar spread for dog homes: 72 percent, 76 percent, and 65 percent. 

So the message is: for a healthy baby keep your pets outside letting them in once in a while to bring in dirt that builds up a baby's immune system. Seems kind of unfair to the pet.