Understanding Tongue Straps for Horses with Breathing Issues

Question
hello sir, once i posted you a question regarding training a horse with breathing problem. you said that you would be using a tongue strap for a horse with breathing problem. i dont understand how does tongue prevents a horse from intake of oxygen? please explain me sir!!!!!  

Answer
hi  when you use a tongue tie on a horse it keeps the horse from moving his tongue around and prevents him form getting his tongue in the way of his breathing. like it keeps the horses tongue out of the air way so he can breath normally. thanks ED HESS