One of my previous dogs was a top scrounger. He could catch and eat a bunny in a sitting leaving nothing, no hair, bones, claws, teeth, guts, blood were left, he ate it all. The procedure is simple, start at the head and when you reach the tail stop. We had to reduce his evening feed for a while but after he eradicated the rabbits his weight went back to normal.
At another time I noticed him vanishing for an hour and then re-appearing to have a sleep. This was repeated several times until I followed him. He was working through the carcass of a road kill roo. He had eaten the head, neck and one forearm and shoulder, clearly using the same procedure. I took it away.
This is not a 80kg Cujo but a 18kg Kelpie. People don't realise how efficient working breeds are until they see them in action.
Yes I am very careful with parasite medication for my dogs.