Select Breeders Services (SBS) and its affiliate labs require current negative test results for specific diseases for stallions presented to our facilities for freezing which can include Contagious Equine Metritis (CEM), Equine Viral Arteritis (EVA) and Vesicular Stomatitis (VS) as well as a negative Coggins. Depending on the facility, the tests may be required prior to the stallion’s arrival or performed at the time of collection. What does all that mean and why are these negative tests necessary? In this article we will discuss the way these diseases are transmitted, how they can be prevented, why we require they be performed and provide examples of what can happen if an outbreak of these diseases occur.