My 9month old male Weimaraner Felix (see what I did there?) occasionally sits and sort of huffs and puffs. Like when someone is in tears and they can't catch their breath if you can envisage, his cheeks puff in and out at the time. He will do it for about 30sec, all the time still wagging his mad full length tail, he is fine before and after and isn't ill at all or out of sorts. Any one have any ideas why he might be doing this?