Ok not trying to stir the pot but what about hounds? my lacys hop in the back no prob...now the hound he just looks at them like "hey howd they get up there"...i say "Tader load up" an pull him up by his collar been doing it since he was 3months old..the thing is hes 5 months old an 40lbs..hes fixin to get to heavy for man handling...is it just a hound thing an he'll figure it out eventually or am i doomed to having to heave a 80-90lb dog into his box?
here is how I used to do it with this taller bed...but it is a pain in the rear for me to crawl up in the truck bed with the tailgate down...
if you know the pup is old enough to jump in then use a choker chain on a lead...crawl up in the bed and give the command to load up while pulling the dog up towards the bed...make it so he is hanging for a while and you just barely give enough assistance so that he makes it in...the idea is to make it so uncomfortable that he will try extra hard to load up then and all the other times...when he gets it then you can do the same without having to get in the bed...
but I think jsh has the right idea, at least I think it is...