Just make sure they are potty trained!!!
Hog hunters have enough crap to worry about without having to keep up with a diaper bag!

I was pretty fortunate when I was young in that my property was attached to an 8000 acre track of land that I had permission to hunt on. My son would ride with me on my horse right from my own yard to hunt. When it was time to tie a hog, I would put him in a tree in case my horse spooked. He was 3.5 years old when I started.
It all has to do with the kid and how serious they are about it. He watched the dogs as closely as I did and would tell me when he thought they were in sign and going to find a hog. He was usually right.
Kids can be a pain in the woods but they are usually amazing.