planning first 3 day backpacking trip in the whites in september with our 7 year old lab and almost every "hike with your dog" article online reads like it was written by someone who has never actually carried a tent, looking for real perspective from anyone who has done overnights with a dog this age

Quick context. Cooper is our 7 year old black lab, 72lb, no joint issues on his last orthopedic check in march, generally fit, walks 3 to 5 miles every day rain or shine, and we do 6 to 9 mile day hikes in the local state park most weekends. he loves it, he is in good shape for his age, and he has been our regular hiking partner for the last five years. day hikes are dialed in. multi-day is new.

my husband and i are doing a 3 day 2 night loop in the whites the second week of september. the loop is about 22 miles total, longest day is 9 miles with 2,200 feet of gain, both camps are at established backcountry shelters with reliable water within a quarter mile. weather should be cool (highs 60s, lows mid 40s), which is honestly part of why we picked september for the first trip with him. we have done overnights together before but never with the dog. i have read about 40 blog posts on hiking with dogs and most of them are content marketing for dog packs and they all say the same useless things like "bring water" thanks.

the things i cannot get a real answer on. one, what is the realistic pack weight ratio for a healthy 7 year old lab on a multi-day trip, the standard 10 to 15% number i see everywhere is based on day hike data and i cannot find anything specific to 3 consecutive trail days with the pack on for 8 to 10 hours at a time. two, paw protection on white mountain granite specifically, do real people use boots all four feet, just the front, or is musher's wax adequate for a dog whose pads are already conditioned from regular hiking. three, calorie load for a working dog on consecutive trail days, do you double his ration, triple it, what does the actual experienced answer look like, and how do you carry that much extra kibble. four, daily mileage limits for the age, is 9 miles with 2,200 of gain on day two with overnight recovery a realistic ask for a 7 year old lab or am i being optimistic about what he can sustain three days in a row.

any other risks i havent thought of, please flag them. i would much rather hear "you missed X" now from someone who has actually done it than figure it out at mile 6 on day two. happy to share the specific gear list and the exact route if it helps people give specific advice