There are a few places that you shouldn't miss that your dog will be too far away to wait for you indefinitely - namely the Upper Flats. But most of the river is narrow enough that you can park him on the bank and go back and forth to him if he isn't happy. Some people bring their well-behaved dogs, and even on a float, if the guide permits and they are well-behaved. I think a lot of issues are with toenails on the bottom of the boat, so a strip of carpet should help that. The "braids" should allow him to sit on the bank and wait for you, as should most of the "cable hole" and "baetis bend".