EIA and Coggins Test Requirements in Wisconsin: What Horse Owners Need to Know

Equine Infectious Anemia is one of the most tightly regulated diseases in the horse industry, and Wisconsin takes that regulation seriously. Whether you own a single trail horse or manage a boarding facility, understanding the state’s testing requirements can protect your animals, keep you legally compliant, and prevent a disease outbreak that has no cure and no vaccine.

Wisconsin’s rules are codified under Wis. Admin. Code Ch. ATCP 10, administered by the Department of Agriculture, Trade and Consumer Protection (DATCP). This guide walks through every major requirement — from which animals must be tested to what happens when a horse tests positive.

What Is Equine Infectious Anemia (EIA) and Why It Is Regulated in Wisconsin

Equine Infectious Anemia, commonly called EIA or swamp fever, is a viral disease caused by the equine infectious anemia virus (EIAV), a lentivirus in the same family as HIV. EIA is an infectious, potentially deadly virus that affects the immune system of animals in the Equidae family. The horse, Equus caballus, along with donkeys, mules, and other members of the family Equidae, can all contract the disease.

It spreads primarily via blood-feeding insects like horseflies and deerflies, as well as contaminated equipment such as needles and surgical tools. Once a horse has been infected with the virus that causes EIA, it carries the infection for life and can transmit the disease — via fly bites — to other horses nearby.

Symptoms range by stage: the acute form brings high fever, weakness, swelling, and anemia; the chronic form causes intermittent fever, weight loss, and anemia; and inapparent carriers show no visible signs but remain contagious. There is no cure or vaccine for EIA, making testing the only tool for disease prevention and control.

EIA is a reportable animal disease in all states, and Wisconsin has specific requirements for testing. Because infected horses remain lifelong carriers and show no symptoms in many cases, mandatory testing is the only way to identify and contain the disease before it spreads through a herd or across state lines.

Key Insight: Because asymptomatic horses can still transmit EIA, a horse that looks and acts completely healthy may still be a carrier. Annual testing is the only way to know for certain.

Which Animals Require a Coggins Test in Wisconsin

EIA testing requirements in Wisconsin apply to all equines, including donkeys, mules, zebras, and wild horses and asses. The term “equine animal” under Wisconsin law covers every member of the family Equidae, not just domestic horses. If you own or transport any of these animals within or into Wisconsin for regulated activities, the testing rules apply to you.

There is one notable exemption for young animals. No EIA test is required for nursing foals accompanying an EIA-negative dam, as long as the nursing status is identified on the Certificate of Veterinary Inspection (CVI). Once a foal is weaned, it falls under the same testing requirements as any other equine.

Other limited exemptions exist for animals going directly to a slaughtering establishment, animals consigned to a licensed dealer (who must then test within 10 days), and animals sent to a market operator (who must test within 4 days of arrival). Until negative EIA test results are obtained, the animal dealer may not consign or sell the animal, move it from the dealer premises, or allow it to commingle with any other animal on the premises.

When a Coggins Test Is Required in Wisconsin

Wisconsin law triggers EIA testing requirements in three main situations: sale or transfer of ownership, participation in exhibitions or organized events, and movement into the state from out of state. Understanding which situation applies to your horse tells you exactly when you need to have a current negative test on file.

Sale or transfer of ownership: No person may purchase, sell, or transfer ownership of any equine animal in Wisconsin unless the animal has tested negative for equine infectious anemia within 12 months from the date the blood was drawn for the test to the date of purchase, sale, or transfer, and the official test report accompanies the animal.

Fairs, exhibitions, and organized trail rides: For fairs and exhibitions, organized trail rides or training seminars, or a sale or transfer of ownership, equines must have proof of a negative EIA test within the previous 12 months. No EIA test is required for nursing foals accompanying an EIA-negative dam as long as the nursing status is identified on the CVI.

Movement within Wisconsin for special events: Per DATCP rules, horses and other equine animals moving within Wisconsin require proof of a negative EIA test within the previous 12 months for certain activities, including special events on DNR properties such as horseback dog trial events and organized trail rides. This testing requirement does not apply to personal trail rides that do not meet the definition of a special event.

Pro Tip: Even if the state does not require paperwork for a particular activity, event organizers — including fair boards, show managers, and trail ride coordinators — may impose their own testing or documentation requirements. Always check with the organizer before you load up your trailer.

How the Coggins Test Works and Approved Testing Methods in Wisconsin

The Coggins test, or agar-gel immunodiffusion test, is internationally recognized as the standard to which all other tests are compared for diagnosing EIA. Developed in the 1970s by Dr. Leroy Coggins, it remains the gold standard for EIA diagnosis. A second method, the ELISA (Enzyme-Linked Immunosorbent Assay), is faster but requires AGID confirmation if it returns a positive result.

Only authorized personnel may collect the blood sample. The person collecting an EIA test sample must be an accredited veterinarian; if the veterinarian performs the test in Wisconsin, they must also be a Wisconsin-certified veterinarian. An authorized employee or agent of DATCP or the federal bureau may also collect samples.

The process itself is straightforward. For a Coggins test to be completed, a licensed veterinarian needs to draw the blood and take photographs of the horse’s left side, right side, and face. The veterinarian must also document all markings on the horse. The sample is then submitted to an approved laboratory.

The person who collects the EIA test sample must identify the sample with the official individual identification of the equine animal from which it was collected. EIA tests must be conducted at a laboratory approved by the department or the federal bureau. Starting April 15, 2020, all veterinarians and laboratories must use USDA-approved EIA test forms for regulatory compliance.

Test Method	Full Name	Turnaround Time	Confirmation Required?
AGID (Coggins)	Agar Gel Immunodiffusion	24–48 hours	No — standalone official test
ELISA	Enzyme-Linked Immunosorbent Assay	Faster than AGID	Yes — AGID confirmation needed if positive

Once the laboratory completes testing, it will forward your horse’s test results either directly to you or to your veterinarian. A negative result is recorded on a formal certificate used for compliance with state and event requirements. Digital platforms such as GlobalVetLink allow veterinarians to submit EIA tests electronically and give horse owners online access to their certificates from any device.

Interstate Movement and Import Requirements in Wisconsin

If you are bringing a horse into Wisconsin from another state, you must meet specific import requirements set by DATCP under Wis. Admin. Code § ATCP 10.36. These requirements apply regardless of whether the move is temporary or permanent.

All equines entering the state of Wisconsin are required to have a Certificate of Veterinary Inspection (CVI) and a negative Coggins test within 12 months. If you are moving your equine to Wisconsin permanently, you are required to have a valid 30-day CVI with a negative Coggins test listed on it. If the Coggins test listed on your equine’s CVI expires before the CVI expires, the CVI becomes invalid when the Coggins expires.

The EIA test date and result must be written on the CVI. Most horses entering Wisconsin do not need an import permit, but there are exceptions. Horses entering Wisconsin do need an import permit if they are part of a circus, are rodeo stock horses (though a permit is not required for horses owned by individual rodeo participants), are traveling as part of a menagerie of multiple species for exhibit or competition, or are exotic equines such as a zebra or wild ass.

There is also a limited exemption for short-term visits from neighboring Minnesota. Equines from Minnesota that will be in Wisconsin for a trail ride, horse show, or exhibition for less than 7 days with no change of ownership do not need a CVI, though a CVI may be required by the organizers to participate in the event, and the equines will still need proof they meet the EIA requirements.

Animals going directly to a veterinary facility for treatment and returning immediately to their state of origin are also exempt from the CVI requirement. No person may import an equine animal that has already tested positive for equine infectious anemia.

Important Note: Reciprocity matters. Under ATCP 10.36(2)(e), an out-of-state horse attending a Wisconsin trail ride or show without a full CVI must originate from a state that allows Wisconsin horses to attend similar events in that state under comparable conditions. Check with DATCP if you are unsure whether your state of origin qualifies.

What Happens When a Horse Tests Positive in Wisconsin

A positive EIA result triggers an immediate and serious regulatory response. No person may move an equine animal that tests positive for equine infectious anemia, except as provided by law. DATCP shall summarily quarantine every test-positive animal. The quarantine notice must include written notice of the positive test result, notice that the owner may request a retest, notice that the state veterinarian may issue a branding order, and notice of specific quarantine conditions.

If the positive horse participated in an event before the test result was known, the response widens. If DATCP finds that a test-positive animal has participated in an event where it could have exposed other equine animals, the department shall notify the event sponsor. The event sponsor must then notify all other event participants that their animals may have been exposed.

DATCP may also summarily quarantine equine animals that may have been exposed to a test-positive animal. This means that even horses that tested negative could be placed under quarantine restrictions if they shared space or a fly zone with a confirmed positive horse.

For horses that test positive after entering Wisconsin through a sale or market, the owner or custodian faces a narrow set of options under ATCP 10.36(5)(b): euthanize the animal on the premises where it is located; ship the animal directly to a slaughtering establishment for slaughter under a DATCP permit; or return the animal to its state of origin under a DATCP permit.

Quarantine, Euthanasia, and Isolation Rules in Wisconsin

Wisconsin’s isolation rules for EIA-positive horses are strict and grounded in the biology of how the disease spreads. Because EIA is transmitted by biting flies, physical distance from other horses is the primary control mechanism.

An equine animal quarantined under DATCP rules shall be kept in a stall or other facility from which flies are effectively excluded, or at least 300 yards from all equine animals that are not known to be infected. This 300-yard standard reflects the typical flight range of the horseflies and deerflies that carry the virus between animals.

No person may move, sell, or transfer custody of an equine animal quarantined under these provisions without a permit issued under ATCP 10.89(6). Attempting to sell or relocate a quarantined horse without that permit is a separate violation of state law.

Owners who believe the initial positive result was in error have a right to request a retest. The quarantine notice must include notice that the owner or custodian may request a retest under ATCP 10.35(5). If the retest also returns positive, the options narrow to euthanasia, slaughter under permit, or — for horses that entered from out of state — return to the state of origin under permit.

Horses that test positive for Equine Infectious Anemia must either be euthanized, branded and strictly quarantined more than 200 yards away from other horses for life, or transferred to a research facility. Wisconsin’s own administrative code sets the quarantine distance at 300 yards, which is more protective than the 200-yard federal minimum.

Important Note: A person adversely affected by a quarantine order may, within 30 days after the quarantine is served, request a hearing as provided under ATCP 10.89(6). If you receive a quarantine notice, consult a licensed veterinarian and contact DATCP immediately to understand your options and timeline.

Penalties for Non-Compliance in Wisconsin

Failing to comply with Wisconsin’s EIA testing requirements is not a minor administrative matter. The state’s animal health laws under Wis. Stat. Ch. 95 and the accompanying administrative rules under ATCP 10 carry real legal consequences for violations. These can include civil forfeitures, denial of entry to events, and forced removal of animals.

Moving a horse without the required negative Coggins test — whether for a sale, exhibition, or import — puts you in direct violation of ATCP 10.35 or ATCP 10.36. Event organizers and state inspectors have authority to deny entry to any equine animal that cannot produce a valid, current negative test certificate. If a horse is found at an event without compliant documentation, it may be removed from the premises.

For sales and transfers, the consequences are more severe. If a horse is sold without a current negative EIA test on file, both the buyer and seller may be subject to enforcement action. An equine animal consigned or sold to an animal dealer must be shipped directly to slaughter or tested within 10 days. Until negative results are obtained, the dealer may not consign, sell, or move the animal from the premises or allow it to commingle with any other animal. Violating this hold requirement is a separate enforceable offense.

Moving or attempting to transfer a quarantined horse without a DATCP permit is also a direct violation of state law. A person adversely affected by a quarantine order may, within 30 days after the quarantine is served, request a hearing on the quarantine as provided in ATCP 10.89(6). Outside of that formal process, no unauthorized movement is permitted.

If you have questions about your specific situation, contact the Wisconsin DATCP Division of Animal Health directly. The agency’s toll-free hotline is (800) 422-7128. You can also work with an accredited, Wisconsin-certified veterinarian to ensure your animals are tested, documented, and compliant before any movement or sale takes place.

Staying current on EIA testing protects more than just your own horses. The severe nature of EIA alongside how easily it is transferred between animals makes regular Coggins testing the best defense for protecting not only the health of individual horses, but of all horses across the country. If you own horses in Wisconsin, annual testing is one of the simplest and most effective steps you can take as a responsible equine owner.

For more information on Wisconsin animal regulations and wildlife, explore our guides on livestock trailer requirements in Wisconsin, rabies vaccine requirements in Wisconsin, and fishing license requirements in Wisconsin. You may also enjoy reading about the fastest horse breeds or exploring Wisconsin’s diverse wildlife through our articles on types of hawks in Wisconsin, types of owls in Wisconsin, and types of herons in Wisconsin.