Hi JRod. I use one for my chow and my golden retriever in poor weather. I intend to use it on Sumo when he reaches about 19 months or so.
I only use it on a slow speed and without an incline. Start really slow for short periods of time and reward sessions with a nice treat!
I have never put my dogs on for more that 15 minutes and always supervise. Also, I do not recommend chaining your dog to the handles of the machine. I've seen people on TV doing this with Pit Bulls. It looks potentially dangerous, should your dog slip.
Good luck.
