Our columnist tells how to best prepare—whether you’re buying or selling—for what is sometimes a dreaded experience.

Buying or selling a horse can be a traumatic experience. On one side the buyer has found what he hopes is the perfect horse and desperately wants it to be “The One.” On the other side of the fence is the seller, who hopes to move a horse to a good home and make some money in the process. There often are a variety of advisors or agents on either side of the equation who are expected to give their professional opinion on the suitability of the horse.