I also use the medium  Mountain Smith K-9 for my 60 lb Malinois. She prefers this pack to a regular harness, and the handle is great for creek crossings. It has a couple of nice spots for a bowl outside, and the pockets are very water resistant. I sprayed it with nik-wax for keeping out water and pack food and snacks in ziplocks. This pack will hold fives days food, snacks, small blanket, and a tennis ball. Once adjusted it,s easy on and off for breaks.