I have a almost 5 year old Percheron that I have been riding since this past October. I have NEVER had a problem putting the bridle on him, until 2 weeks ago. Now he throws his head way in the air and clenches his teeth together. I have been tying his head low so I can bridle him, and once it's on, he is fine.
He had his teeth checked in September and he was fine then. Never a problem when I am riding him, well not with his head anyway. He responds very well to the bit, I am using a single jointed snaffle, which he chews on constantly, but always has.
Oh, the biggest problem, is that he is 19 hands so when he throws his head up, it is WAY UP THERE!