In the situation stated i would make a shot on the animal. I like to have my hairs set just in front of the animals shoulder and move with the critter. How much in front of the shoulder obviously depends on the speed of the animal. I am quite confident with this method and it has been pretty sucessful for me in the past. As stated earlier it just really depends on how confident you feel at the time. You don't get out of bed in the morning and say okay today if i see a running animal i will not shoot. It all depends on how the situation presents itself and you don't have alot of time to react or think about it. You can't sit and hum and ha about it, either you quickly shoot or ya don't.