The key is networking. By attending continuing education programs offered by the American Association of Equine Practitioners and other institutions, your veterinarian might be familiar with someone in that area, or at least know someone who knows someone who is a good equine practitioner. Second, interacting with fellow horse owners is a good way to find information. Ask them if they have traveled to your planned destination and if they had to find a veterinarian away from home. Their experiences can be a great asset to you.
Word of mouth is an excellent resource for information about equine practitioners.
A third way to find a veterinarian who specializes in equine practice is through the American Association of Equine Practitioners. The AAEP, in conjunction with the Bayer Corporation, has developed a national locator service for participating AAEP veterinarians. The sole objective of this program is to help horse owners locate participating AAEP member equine veterinarians anywhere in the United States and Canada. When a horse owner calls this number, an operator will ask for the caller's location or zip code. Then from a computer, the operator pulls up that area and finds the name, address, and phone number of the AAEP veterinarians who have agreed to participate.