What are the theories behind a horse having a guttural pouch?

Question

What is it really used for?

Answer 1

Unfortunetely, my intelligence (not that it's all that high to begin with) has it's limits and this question is beyond my scope. lol

I have read a little bit here and there about the Guttural Pouch, including an article about possible brain cooling. But it appears that overall, the most brillant minds are complexed as to its true purpose.

Answer 2

What" theories" are  you asking for!!

I do not  understand what you want, Please edit more,

Answer 3

They're unique to equids, and other than providing a great place for stubborn infections to brew, I don't think the purpose of their existence has yet been figured out.  Maybe there's some new information from research which I don't know about.  They're outpouchings of the eustachian tubes, but, again, I don't think any one has figured out why they're there.  I hope a brilliant veterinarian answers this question.