We had two Gooseneck Flatbed Trailers modified with traveling cages for our hunting dogs. We used to put them in the back of the pickup that has a camper, but the cages didn’t fit very well and when we needed to haul five dogs, we really only had room for four.  The utility trailer is easy to hook up and the dogs each have their own place.  That keeps peace in the family.  It wasn’t very expensive to have the trailers modified and it sure has made it easier to get all the dogs where they are supposed to be.