My mystery with a canine malady

Our Aussie keeps a ready supply of deer skulls and legs, bird carcasses, rabbit heads, squirrel tails, pork chop bones, dead raccoons and groundhogs, and various other animal parts strewn all over the yard, just in case I guess. I think the cat is responsible for the rabbits and squirrels, but the dog drags up the rest. I haul it off, he brings it back or finds something new. I fully expect at some point in the distant future some archaeologist is going to discover that the hunter-gatherers were living here in the 21st century. All that being said, he has yet to find something he can't eat or use for entertainment.