Hm... I think deer can eat digest some meat, they just aren't good at chasing down animals or breaking through the skin. But they do pose a risk to ground nesting birds since deer might eat the eggs or hatchings. Idk about any other animals, but I remember reading an article that worried that deer might catch diseases by eating dead squirrel/rabbit carcasses. So it might eat those too if they were dead, but maybe not in its entirety since breaking though the skin must be hard with flat teeth...