In Michigan, when an equidae is diagnosed as EIA positive, the individual and others on the same premises are placed under quarantine. While under quarantine, no equine may be moved off the premises without permission from the Michigan Department of Agriculture. Intentional violation of the quarantine is a felony under section 287.744 of the Animal Industry Act of 1987, and is punishable by fines or imprisonment.

The Michigan Department of Agriculture will do all testing of positive animals, and appropriate investigative testing of other equine on the premises at no charge to the owner. The owner may choose to have an accredited private veterinarian conduct the retesting, but it will be at the owner's expense.

Four options are available to the owner whose animal has tested positive. The option chosen by the owner must be approved by the department before being carried out. The options are:

1. Move the positive individual to a location that is preapproved by the department, and is a minimum of 1/4 mile away from the other equine, and quarantine the individual at this new location. The 1/4 mile separation of equids takes advantage of the migratory range of biting flies by placing other equine outside the normal range of the insects, reducing their risk of infection.

2. Move the positive individual to an insect-free enclosure and quarantine the individual there.

3. Euthanasia with proper disposal witnessed by a Michigan Department of Agriculture employee or accredited veterinarian.

4. Ship to slaughter, under procedures approved by the director, and with the appropriate state or federal movement papers. There are only a few slaughter facilities in the United States which are allowed to accept EIA positive horses.

If not euthanized or shipped to slaughter immediately, equids must have a "34A" freeze brand (no less than 2 inches in size) applied to the left side of the neck. The freeze brand is a relatively painless procedure that results in white hair growth at the brand site.

Once the positive animal is removed from the quarantined premises by one of the above methods (or by natural death and disposal), further testing of the remaining animals must be completed for the premises to become eligible for a quarantine release. The following testing schedule is used:

1. Between November 1 - April 30, the herd may be tested at any time and qualify for release if all test negative for EIA.

2. Between May 1 - October 31, the herd may be tested a minimum of 30 days after the positive animal has been removed. If all animals test negative, the herd qualifies for a quarantine release.

If the positive animal dies while under quarantine, the Michigan Department of Agriculture must be notified so that a department employee may be sent out to verify the animal's identity. The body must not be disposed of until verification has been complete.

The Michigan Department of Agriculture may conduct investigations into possible exposures of EIA positive animals to determine the need for additional quarantines and EIA testing.