You can train a dog to do as much as you have time for, and their ability.
I don't know how to train a dog to blood trail, but my last dog would scent trail. I would just point to the last know spot and command "search" and he'd run down the duck, goose, ground hog or deer to it or the hole or last spot he could find scent. Made it easy to find downed deer, real easy to what hole the ground hog ran too that you saw, ect.
"If you can't have fun doing it, it ain't worth doing." my motto
There is nothing better than hunting with friends and then crackin' a couple of cold ones afterwards.