There are three shots I take:
1. Kill shots.
2. Anchoring shots.
3. Central Nervous System shots. (Head/neck/spine)
Type 1 is fatal, but it may not stop the animal from making a temporary escape (100 yards to 2 miles, depending on the animal and terrain).
Type 2 might not be immediately fatal, but it will stop the animal from making any escape.
Type 3 is both fatal and anchoring, but not always possible or advisable.
I very much prefer a CNS shot, but hunting conditions rarely allow them.
Generally, I take a kill shot first. If there's a flight risk in terrain/vegetation that allows the animal to escape, the anchoring shot comes out.
I haven't had to track an animal, to date, but I'd go miles and miles, if needed.
I'll pass on the shot, before I make a compromise and risk a wounding shot.
"Such is the strange way that man works -- first he virtually destroys a species and then does everything in his power to restore it."