I've heard that double-coated dogs should not be shaved. Zoey is not shaved nor do I plan on ever shaving her. Her fur is meant to protect her from the snow and heat. That's the way her fur was made. But Dolly is long-haired and is fairing much better now that she has been shaved for the summer than she did before. I would say, just in my opinion, if the dog has long, bushy hair like on Australian Shepherds, Old English Sheepdogs, etc. I think it is best to shave them for summer. But dogs with insulating fur like Huskies, Malamutes, etc. should not be shaved. That's all my opinion only though.