Only when they die in the wild. Possums will eat any dead animal they can get ahold of. In my youth I've heard stories of people finding a dead horse or cow and all at once see a possum crawling out of the body cavity. A possum trying to eat a living dog is very unlikely. read more
No possums wont and will never eat your dog, they eat insects, roadkill, fruits and berries. Now to get rid of it set up a cage trap by the trash cans and when you catch it take it and release it in the woods or a reservation. read more