Back in the 80's my neighbor's mare foaled and it was a red bag delivery.
She called the vet immediately and he was there quickly and everything was OK.
My mare was due to foal shortly after hers and boy, was I surprised, to see that
my mare was doing the same thing. Lucky for me, my neighbor told me about her
mare's problem, so I knew I needed to get the foal out ASAP. I ripped the bag
open to find his muzzle. The bag was very tough and I had a hard time, but did
get it off his head and then pulled him out as she pushed. He was fine. I was
lucky I guess.
My second child was born that way... placenta previa, or something like
that. We were lucky too.