My older Brittany chases down cottontails like they are standing still. I haven't seen a jackrabbit in MN in a while, but pheasant hunting in SD we see them occasionally. The dog got a scent of one, pointed it, then it bolted. The chase was on in relatively open country. The dog came back exhausted and with no bunny. He even gave me a look of "what the fuck kinda crazy fast rabbits do they have around here?" First time I ever saw a rabbit get the best of him.