I'm a breeder so having an emergency vet is Madatory! I just don't have one, I have 3 !!! I have them posted on my fridge as well as a (human) medicine list you can give to your babies. You just never know when you'll need one and if I can't get ahold of one....I have backup!
It happened to a breeder friend just a few weeks back. She had a bitch begin to whelp and knew there was a problem, paged our vet...and guess what? No return call

He called THE NEXT MORNING

stating the page didn't go thru!!! No way am I going to risk that!!!!
She has backups as well and she did end up having a c section, the baby was breach and her rib cage was stuck on the pelvis!!! All babies lived and mom and babies are fine