Detailed history, including examination of medical and reproductive records.
Thorough physical examination in the stable, including hands-on palpation, listening to the heart and lungs with a stethoscope, and eye examination.
Observation at the walk and trot on lead.
Observation at the canter and gallop, then rest and re-examination.
A Coggins test, which is a blood test for equine infectious anemia, should always be performed. A Coggins test is also almost always required by state regulation if a horse is to be transported across state lines. Your veterinarian can advise you of the current regulations in your area.
Other special diagnostic tests, such as soundness x-rays, blood tests, or examination with an endoscope, may be recommended based on findings of the physical examination. Regional requirements and conditions may also dictate certain tests.
State or country regulations may require vaccination for specific diseases before purchase. These are performed after the decision to buy has been made.