ORIGINAL: IAhuntr
I'd wait until late afternoon. No need to rush. Let him lay up and if you did get a lung he should expire in his bed. If you bump him and he isn't leaving a decent blood trail you'll greatly diminish your chances of a recovery.
Take a nap right now. There is no way I would be heading out to look for him before 2pm. If the temps are in your favor, stay home for a bit and give him some time to bed down. If he was not pushed, I would assume he would bed up fairly quickly. Once he bedded up he will start to stiffen up and hopefully expire soon, but if you bump him he is gone.