I've had Baldies flying down and fly off with fat groundhogs that i have shot . At other times I've watch bluzzards completely eat groundhogs and was gone in 5 minutes . Nature is quite interesting to just watch sometimes.
In my region of the country racoons, foxes, and possums are likely candidates. Of course there is always the possibility of feral hog or even a mountain lion showing up and by water the alligators might take it.
The bald eagles in my area do go after new born lambs and would likely go after something dead.
I had a similar occurence, started at the bullet hole in the chest before i got rid of the body 2 days later it was a 3-4" round hole where the small bullet hole had previously been with no organs left inside the body cavity. thoguht I could smell a skunk that morning could he be the culprit?