I will echo what Airborne said about the horses being a hassle. Taking them on hunting pack trips is more work than fun if you plan on hunting and taking care of them simultaneously. Hopefully if you are renting horses a guide/wrangler is part of the deal. If not my advice is that if you are going with a group of 4 or more for that amount of time is to rotate days as wranglers. One person is responsible for the horse each day and rotate through the trip. There is a laundry list of issues that can come up with horses aside from the daily care they require (injury, thrown shoes, etc). I own horses and have plenty of experience. Personally I have never packed in with my horses for more than a 4 day trip because hunting and taking care of the horses is so much work you are completely exhausted and done after day 4.
Also if you aren't riding them daily they can get bored after a couple days tied to the highline and become quite moody which doesn't help.
Also if you aren't riding them daily they can get bored after a couple days tied to the highline and become quite moody which doesn't help.