DTA, how is a dog being messed up working him that way when he wins in 2 hours, never coming off his feet or taking a deep breath?

Bulldog Connection, yes I have conditioned a dog in such a way, minus the incline.

Purepit, I don't know what aspect of conditioning you think is most vital, but cardio/endurance is the most vital part of any keep. So running a dog at that speed for that time will make the dog in better shape for the most important aspect of the keep. Running on a mill isn't easier than running on the street as running is running. Running the mill is different, of that there is no doubt.

In actuality, whichever form of running allows a man to get his dog in the best possible shape to win consistently is the best form of running. The pads on a dog don't allow for extreme distances because people don't condition them to be such a thing. They just start working the dog, in whichever way, and never stop to consider the pads are like a dog's tires. There are ways to condition a dog's pads for alot more distances than most think, and if that's not good enough, then buy some boots for the feet like sled dog mushers use on their animals.

I'm not sure on sacrificing as a dog isn't going to become weaker due to an emill. It's not going to lose it's natural ability nor it's mouth (if it has any to begin with). An emill is a tool to use, nothing more and nothing less. Some men's understanding are ahead of others, and that allows them to do things others simply can't fathom.