Treadmills and springpoles are not illegal anywhere as far as I know. You can NOT be arrested for owning them.
That said, cops are given guidelines to look for when they suspect that fighting is going on. Here are a few: Springpoles, treadmills, multiple dogs chained in yards, wounds on the dogs, weight pulling harnesses, presence of certian medical supplies. Any of these things can cause the police to question you, but they are not illegal by themselves and without reasonable suspicision you can not be arrested or have your dogs taken from you.
Demo will correct me if I'm wrong on any of this....