Try to avoid seeds and lab blocks, prairie dogs in the wild have a diet mainly of dry grasses so their bodies arn't used to the richness of seed mix and lab blocks. My friend adopted a 2 year old that had been raised on lab blocks and hay and he suffered a painfull death about 4 months later. His liver and intestines were just shot from the bad food.
Not trying to scare you but its safer to stick with timothy hay based pellets like Bunny Basics by Oxbow and different grasses and hays with richer things like lab blocks being a once a month treat and limited fresh veggies.
Good luck and he looks like quite a sweety!!
2.0 ribbon snakes, 0.1.1 bearded dragons, 0.0.2 occellated skinks, 0.01 bibrons gecko, 0.2 redsided garter snakes, Mississippi map turtle, RES turtle & leopard geckos!