Does anyone have any pointers or recommendations for hiking with a puppy? She's about 5 months old and she's done some day hikes (5ish miles) but we'd like to take on a 20-mile loop.
I would talk with your vet. Generally, depending on breed, dog's joints/bones aren't fully developed until at least 1 year if not 2. 20 miles may be too much strain, unless you plan on packing your pup for parts of it.