This article is from the Hiking/Backpacking With Canines, by Terri Watson with numerous contributions by others.
I have a Wenaha pack. It has two parts, a pad that is attached to the
dog with three straps: across the chest, around the body right behind
the front legs, and around the body near the end of the ribcage. The
pack attaches to the pad with a plastic buckle at the center front of
the pad and three velcro strips: one large one down the center and two
smaller ones on the sides. Do not over-tighten the straps as they can
be uncomfortable for the dog and interfere with breathing and motion.
A Wolfhound owner advises, "With Wolfhounds and similarly built
breeds, it is very important to place all weight on the shoulders, NOT
I like the two part pack design because it allows me to quickly remove
and replace the pack during rest stops. I chose a red pack and I leave
the underlying pad on until Tika comes into the tent at night. Should
she get away from me for some reason, the red pad will (hopefully)
identify her as a domestic animal - a valid concern during hunting
season. It also makes her easier to spot in a variety of terrain.