Aleisha, when we have puppies here, you'd think they were killing each other - they get REALLY rough - of course, they are pretty much the same size, but I've never had one of my older dogs actually HURT one of the babies. They seem to know - even if they do look like they're playing too rough. Even my big Romeo - and not especially fond of puppies, is gentle with babies.
By the way he is coming home after living with my grandson for several months. Tony is having some health problems, plus he's working full time and going to school full time, and doesn't have the time for Roms now and Roms is lonely.