Though I have noticed and known that dogs kick and scratch grass after pooping for as long as I know what a dog is, I had always figured it was just for sanitary, like us humans wipe after using bathroom, aren’t we? I’m amazed that dogs have a similar demand for hygiene.
I agree with the territory marking theory, we all at least once saw a dog pees to set the boundary of his territory, so kicking after pooping could be as well for the same reason, but it’s surprising to know that dogs get scent glands in their paws! Wow, how awesome is that!!