I agree that some horses may be yawning because of an eating habbit or something similar, but I am 100% positive that my horse (Dillon) yawns as a behavioral thing. I am known to spend hours in his pasture or just with him in general. He follows me around like a big puppy. If I stand still long enough he will get as close as physically possible and just yawn and lick my hand, etc. And can that boy ever yawn, he rolls his eyes back and opens that mouth as far as possible. It is so cute (also wierd to other people). He is so loving and it is almost as if he is grooming and socializing. He has never bitten me or even attempted and I have had him for over three years, so I know that is not the deal. I believe it is just some horse talk that I have not totally figured out yet. Anyway, I hope this helps or just entertains.. :)
~Sally
~Dillon and Quincy
