PLEASE everyone, take the time to talk with all of the vets close to you AND in the surrounding areas. Find out who has emergency procedures and will come when you need them. And my suggestion is to make that vet your main vet for your horse(s).
I have a great relationship with the vets here in our area and they will come anytime night, day or holiday that I call. Anytime. When I moved here, I took the time BEFORE I had any problems to find out who to call and who would help. And I maintain that relationship by always paying my vet bill. Sometimes I don't pay it right away, but they know I will pay, and I will pay very soon.
So find out the scoop before your horse gets sick or hurt and maintain a good relationship with the vet, and hopefully you will never have to say "my vet won't come".