The AGID test, also known as the Coggins test, is the most commonly used official test to detect antibodies from equine blood against the EIA virus. It is extremely likely that an equine animal that tests positive on one occasion will do so for the rest of its life (except young foals who absorbed antibodies from their positive dam's colostrum).

Michigan law requires that, for interstate movement of equidae into Michigan, the animal tests negative on an official EIA test within 180 days before entry into the state. The animal must also be accompanied by an official interstate health certificate or official interstate certificate of veterinary inspection.

At present, there is no vaccine or cure available.