Not really given the lack of insulation to hold off the sunbake. Open side windows and leave the tailgate open, might even put a reflective cover over the top. Then Home Depot has a pretty good Ryobi series 1 fan that runs quite a while on just one battery. I figured you are looking to cool the dog not yourself at night.
I thought there would be more people that have tried this. The camper isn't that warm with the windows open and a fan blowing on the kennel , I just thought that a exhaust fan might draw the heat out the top.