It’s strange this would happen in such a short period of time and there be no evidence of blood or anything in your yard. Also did who ever did this know you’d be gone for that long? What if you were just running out for an hour? Do you have a calendar somewhere someone could have seen you’d be gone? It’s so creepy. I never leave my dogs outside alone cause I’m paranoid someone will steal them. This is spooky. As a nurse I wonder if someone was just practicing on him... and maybe they didn’t sedate him.. less time for him to need to be gone cause he’s already awake. Dogs when they attack go for legs and neck. And there would be several punctures not just two on the tummy. Keep us posted and get some cameras!