Unfortunately you probably should've waited till the next day once you went past the 1/4 mile range.
I lost one a few years ago like that and will never forget that sick feeling of knowing that he was laying dead somewhere...thing is, is that I bumped him up when he bedded down because I was to anxious and only waited a few hours also.
I'd just go back to where you last saw blood and get a few buddys and walk in stright lines back and forth, kinda like graph paper
Good luck, and keep us posted