If you do not develop a relationship with a vet for routine care, then when you have a 3:00 a m colic, they are not going to come. If you won't call a vet when the horse is sick, and then you call her at 3:00 a m right as she is dying, she won't come. She won't even know how to find your farm.
For everyone out there--- Get regular checkups for your horses. Get the vet to come out. Pay the money. Budget for it just like you do for feed. Budget for emergencies. If you don't have the money, maybe you should either work more or spend less. I have no sympathy for people that wear designer shoes, get their nails done, their hair done, smoke cigarettes, drink beer, and then neglect their horses.