The Graduate Record Exam (GRE) is required by many veterinary schools and other health professions schools/programs, including some M.D./Ph.D. programs. They may require the general test only or the general test and a subject test, e.g., Biology. It is your responsibility to determine if the schools to which you are applying require the GRE and if so, which ones. That information will be found on the individual school web sites. For information on the GRE see http://www.ets.org/gre/.