There are many board certified veterinary specialties. Most fall under two categories, the American Colllege of Veterinary Internal Medicine (ACVIM), and the American College of Veterinary Surgeons (ACVS). In addition there are other specialties such as board certified veterinary ophthalmologists, dentists, behaviorists, and radiologists.
Each Veterinary Specialty Board has their own websites with more information. Visiting thes websites which are linked below can give you access to great information and handouts on the conditions that they treat.
American College of Veterinary Internal Medicine (ACVIM)
This web site form the ACVIM has video describing the value of a specialist. It also has a nice link to fact sheets on diseases and symptoms provided by the ACVIM for conditions that commonly require internal medicine referral care.
American College of Veterinary Surgeons (ACVS) Owner Info
This website from the ACVS has more information about surgical specialists, it has several pet owner links and also has informative handouts with information on various conditions that might require referral to a surgical specialist.
American Veterinary Dental College
American College of Veterinary Dermatologists ACVD
American College of Veterinary Ophthalmologists ACVO
American College Of Veterinary Behaviorists ACVB