Take the rear seat back out and lay it in the baggage, or remove the rear seat completely if you have a A model. A big dog needs more room for his hind end when seated than a human. With the seat back out,his hinder will sit on the baggage floor, forepaws on the seat cushion.
The rear stick isn't a big deal, if his head is in the way, a few good wacks in the nose will wise him up. The rear throttle is a bigger deal. Dogs like to look outside, and rest there nose on the windowsill. If they move their head aft, they knock the throttle to idle, which can be alarming if you are not ready for it.
It's best to train them from pup on, expecially on how to load up. They can claw the hell out of fabric if they miss the door. I have a aluminum plate on the fuselage just behind the lower door just for this.
Hearing loss for the dog is a issue, but if it's a huntin hound, they are probably deaf from shot guns being blasted over their head anyway, so it isn't a big issue.