House cats are living large. A study of 19 million felines across the U.S. and Canada found that cats are fatter than they used to be 25 years ago. While some pet lovers might think it's cute, that kind of weight gain could have serious health effects. Vets say cats that were spayed or neutered weighed more than unfixed animals because their metabolism slows down after the procedure. InsideEdition.com's Mara Montalbano has more.