get a sheet of plywood to fit the floor of your bed and some short pieces of chain with swivel clips and some fence staples. Nail the lengths of chain down with the staples and brad the ends over underneath. Space them apart to where when you lay them down on the board, the clips are around an inch apart. You can carry 9 dogs like this where they can't jump out, lay over the side, or fight.
Sounds like a damn good idea!
On a full size truck, you can get three setups down each side, and three in the middle. The dogs hold the plywood down, and gives them better grip than just the truck bed.