Here is how I find wounded deer and hogs. I shot this hog at night, and Annie found it 16 hours after the shot. Annie trailed the doe about a quarter of a mile and had to cross a stream to find her. Annie tracked the bow doe for about a 100 yards in the dark with no visible blood other than where the doe was hit.
Annie is only 19 months old, but she has already proved to be invaluable to me.