I know Ridgebacks are great dogs. As far as greyhounds go it is absolutely frightening the amount of energy they expend when they are running. As I'm sure dk can attest once they get to running it is an awesome sight. Being in the yard with two of them circling at full speed can be very sobering. You have to make sure to stand clear of their routine path of travel because once they start to circle they become transfixed on running and are not very much aware of anything else. The sod and grass begin to fly after about the first lap and the way they corner is amazing. At the end of our yard their is a large Linden tree and they circle around just in front of it. I'm always afraid that they will crash full speed right into it because they only look straight ahead... very intense especially when the ground is wet. They have worn their own track and they just stick basically to that but Oh my lord how they can fly. As dk said, after about 5 or 10 minutes of this they are eager to come back inside have a good drink and crash for a good 6 hrs or so until they're ready to go again. OK, that's my dog story quota for the week.