I've never minded helping a good dog into the back of the truck . lol but usually I will just hook them up to the bumper with a chain and place their feed and water up in the bed of the truck . they will start to load up to eat and drink . I do this with all my young dogs . but I don't have to worry about them scratching up the paint on my old ford .
I do this as well, but, there is the occasional stubborn inbred yeller dog with a wicked sence of humor who knows how to load, they just don't like being told to. Lol