I just got some shipping boots and I haven't ever used them before. I tried them on my horse and my question is how tight should they be? If I tighten them too much wont it cut off circulation on long trips? But If I don't tighten it enough I am afraid they will start slipping mid trip and he will panic in the trailer with the boot sliding off. Also, are they okay for REALLY long rides. Are head bumpers okay for real long trips?