Dark Horse Tavern » Concerning A Slack Lower Lip ?

hello,

I'm rather new to the horse world, so this may seem like a stupid question. Better safe than sorry, I guess.
I was riding my horse (a fifteen-ish year old gelding) in a bosal today, when I noticed something rather odd. On the right side of his mouth, his lower lip hung as if he had been sedated. He also had his tongue just barely peeking out on the same side. I asked him to flex in the opposite direction, and his mouth looked normal. I look at the right side of his mouth again, and... slack. I'm worried that this may be an issue with the bosal, but he's never done anything like this before. Should I be concerned?

Please help.
Thanks!

I didn't find the right solution from the Internet.

References:
http://www.horseforum.com/horse-health/c...wer-lip-766161/


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