I agree dogs will hide injuries and soreness and most anything that could be perceived as a weakness. It is completely natural.

I like to know the dog long before the work begins. I like to see the strides and the gait when he is perfectly healthy and well rested. Once I get a feel for how that particular dog carries himself I know when something changes. Usually the gait is a give away to an injured leg, injured muscle or foot/paw. Anytime the dog favors a limb it is time to stop and figure out why. There is nothing good on the other end of working a hurt dog.

It is hard to stop the dog on that perfect point every day. It takes time and experience and doing lots of dogs. It is always best to err on the side of not enough than too much. Lots of people work the dogs like they are machines and do not realize the most important of work is rest. Without rest and recovery the work dwindles and the dog is a shell of himself in very little time.

In the beginning and after a few keeps the conditioner will learn to recognize signs. In time the dog will dictate the amounts and those amounts will be based on the dogs individual abilities on a given day. The keeps then become tailor made for the dog being worked. EWO