Hey narc1370,
Great question. I've been backpacking in all seasons with dogs for more than 3 decades, and so far so good. Well, I should say that the only injuries were minor. They lead to an important part of your question, so I'll begin there. Twice my dog Bearzy has broken, or had damage to his front foot dew claws. Just last trip this happened:
100_1078.JPG
See the break of dew claw in upper frame. For this injury I used a very sticky type of band aid first, then some of that soft, stretchy pink tape to provide cushion, and wrapped over that with tough white medical tape. It stayed on fine. This happened a couple summers ago, and here's what the fix looked like:
100_2554.jpg
100_2571.jpg
So, it's good to plan a med. kit for the dog too, and Russ, LincolnB, WD and others can add detail to this. These wraps are probably the main req., and I'd add that you should bring enough to rewrap daily, or sometimes more if they are worn/torn off in icy snow crust, or scree. LincolnB gave me a very helpful link to a dog bootie option I like very much, and intend to use. Here:
https://www.amazon.com/gp/product/B07J5 ... UTF8&psc=1
Dog booties that cover the dew claw are the ones you want, and you'll have to study all of the bootie options if you go that route. Note Bearzy, and many dogs do not need to use booties. Helps if the dog already has toughened paws. These cheap, and light booties are worth having in the med kit though.
This is long enough, so I'll curtail it here, just adding that winter warmth is a big deal. I have this sort of jacket for Bearzy, and he sleeps on my extra clothes, or an airline blanket, on top of his own ensolite pad, under my very warm z-bag, which I open up to serve as a quilt over us both.
100_0979.JPG
Note sleeping set up, with Bear's light blue, 1/2ensolite pad, usually piled with my down booties, jackets, and anything else warm. My using an inflatable pillow has allowed me to dedicate extra clothing to Bear's bed-- I used to make my pillow out of it.
I am looking forward to other's ideas on the med kit, best food, harnesses, dog packs... Thanks for the post narc1370. Ian.