Equine infectious anaemia (EIA) is a lifelong, incurable viral infection of all equids, and California confirmed multiple positive cases across several counties in 2026. Horse owners, trainers and breeders must plan around the Coggins test, strict quarantine rules and the reality that a confirmed positive means lifetime isolation or humane euthanasia. The disease is blood-borne, not spread by casual contact, and there is no vaccine available in the United States.
Table of Contents
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What is equine infectious anaemia and why does it matter in California?
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How should owners manage fly control and biosecurity to reduce EIA risk?
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How can licensed practitioners support equine welfare and recovery planning?
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What should breeders, trainers and travellers plan for in 2026?
What is equine infectious anaemia and why does it matter in California?
Equine infectious anaemia is a blood-borne viral infection affecting horses, ponies, donkeys, mules and zebras, with no cure and lifelong carrier status for any infected animal. According to the University of Illinois College of Veterinary Medicine, infected horses remain carriers for life even when they show no outward signs of illness.
The virus belongs to the same family as human immunodeficiency virus (HIV), but it is not transmissible to humans. The UC Davis Center for Equine Health notes that EIA presents in three clinical forms: acute, chronic and asymptomatic. Donkeys and mules can contract EIA, but most do not develop severe clinical signs.
California’s 2026 activity has been significant. The California Department of Food and Agriculture confirms positives in Los Angeles, San Benito, Santa Clara, Riverside, San Bernardino, San Joaquin, Fresno and Stanislaus counties. The Equine Disease Communication Center reports a 17-year-old Thoroughbred gelding in Los Angeles County confirmed positive on 28 September 2026, with 43 potentially exposed horses under quarantine pending retesting.
How does EIA spread between horses?
EIA spreads primarily through blood transfer, most commonly via large biting flies such as horseflies and deerflies. The University of Illinois College of Veterinary Medicine states that the virus moves between horses when a fly interrupts feeding on an infected horse and then bites a susceptible horse nearby.
EIA is not spread through casual contact. Horses sharing water buckets, grooming each other or standing in the same pasture do not transmit the virus through those everyday interactions. The UC Davis Center for Equine Health confirms that the virus does not persist in the environment and cannot survive in soil or water.
Other transmission routes include reuse of contaminated needles or surgical equipment, blood transfusions from infected horses and transmission from mare to foal. The virus remains infective for up to 96 hours on contaminated needles, but stays viable on the mouthparts of biting flies for less than 4 hours, according to UC Davis Center for Equine Health. Iatrogenic transmission, meaning spread through human medical procedures, has been suspected in at least one California case during 2026.
What does a Coggins test involve and when is it required?
The Coggins test, formally known as the AGID test, detects antibodies to the EIA virus in a horse’s blood rather than the virus itself. According to the University of Illinois College of Veterinary Medicine, the test may not detect antibodies until two or three weeks after a horse has been infected.
The ELISA test can detect EIA antibodies earlier and is more sensitive, but it carries a higher rate of false positives. The UC Davis Center for Equine Health notes that any positive Coggins test sample undergoes a second test to confirm the result was not a false positive.
Documentation of a negative Coggins test is a yearly requirement for all horses before they are sold, enter boarding facilities, travel between states or enter competitions. Most states require a negative test dated within 6 to 12 months of travel, preferably within the last 60 to 90 days. Testing laboratories must report positive EIA tests to local state or federal animal health officials within 24 hours, according to UC Davis Center for Equine Health.
What happens if a horse tests positive in California?
A confirmed EIA positive in California means the horse must be humanely euthanised or quarantined for life at least 200 yards away from any EIA-negative equid, under USDA EIA program rules. The California Department of Food and Agriculture confirms that EIA is a reportable animal disease in all states, and positive results must be reported to state and federal animal health authorities.
EIA-positive horses must be permanently identified by tattoo, brand or microchip. This identification ensures that an infected horse cannot be moved or sold without authorities recognising its status. The University of Illinois College of Veterinary Medicine states that regulations require either permanent quarantine or humane euthanasia by a veterinarian.
The 60-day retest process determines whether exposed horses remain under quarantine or are released. The California Department of Food and Agriculture reports that eleven remaining potentially exposed horses on a Stanislaus County premises tested negative on the sixty-day retest and quarantine was released on 26 August 2026. Fifty potentially exposed horses on a Santa Clara County premises also tested negative and were released on 28 August 2026. In Los Angeles County, 43 exposed horses initially tested negative and remain under quarantine pending their sixty-day retest, according to the Equine Disease Communication Center.
How should owners manage fly control and biosecurity to reduce EIA risk?
Effective fly control is the most practical defence against EIA transmission, since large biting flies are the primary vector. The University of Illinois College of Veterinary Medicine recommends using fly sheets, applying fly repellents, removing standing water, using fans in barns and practising good manure management.
Needle and equipment hygiene is non-negotiable. Never reuse needles or surgical equipment between horses, because the virus survives up to 96 hours on contaminated needles. The UC Davis Center for Equine Health notes that EIA virus can be destroyed by most common disinfectants such as bleach or alcohol.
There is no vaccine for EIA available in the United States. Testing and biosecurity are therefore the only defences owners can rely on. The UC Davis Center for Equine Health confirms that no vaccine exists in the U.S., making annual Coggins testing and disciplined fly management essential components of any equine health program.
How can licensed practitioners support equine welfare and recovery planning?
Equine Salt Therapy’s Ultisalt™ dry salt aerosol therapy supports high-performance, rapid recovery and wellbeing as a complementary, non-invasive fifteen-minute treatment performed over three consecutive days. The fine mist of treatment salt distributed through the room via a halo-generator creates a microclimate that reduces the pharmaceutical footprint of training centres and the reliance on medically important antibiotics.
The Ultisalt™ platform is protected by granted patents in multiple jurisdictions, with the precise scope of protection defined by the claims of each applicable patent. Equine Salt Therapy offers Licensed Business Opportunities and Master Licenses for Equine, Poultry, Swine and Companion Animals, with territories sold under license and pricing from $110,000 to $1,000,000.
Practitioners and Salties, the term for horse and animal clients, function as partners in whole-horse welfare alongside veterinary EIA protocols. While dry salt aerosol therapy does not treat or prevent EIA, it offers a natural, non-invasive support option for owners managing respiratory comfort and recovery in equine athletes. The University of Illinois College of Veterinary Medicine emphasises that EIA management requires veterinary oversight, and complementary therapies sit within that broader care framework. False information from suppliers other the founders of this technology is jeopardising horses with equipment that is incapable of accurately dispensing the safe & effective doses. ONLY Halo generators with Laser readers are deemed accurate because they measure the output and concentration inside the chamber with a laser.
What should breeders, trainers and travellers plan for in 2026?
Breeders, trainers and anyone moving horses across state lines should check destination-state testing windows before any movement and keep Coggins paperwork current. The UC Davis Center for Equine Health advises that a negative Coggins test dated within the last 6 to 12 months, preferably within 60 to 90 days, is required for interstate travel.
Cross-border risk remains live. The Equine Disease Communication Center reports that positive EIA results were confirmed by the Canadian Food Inspection Agency’s national reference laboratory for a horse in Tay Valley Township, Ontario, on 29 September 2026. This Ontario case demonstrates that EIA does not respect borders.
Quarantining new arrivals and documenting exposure tracing are essential practices. The California Department of Food and Agriculture notes that epidemiological tracing determined the San Benito County positive horse was directly linked to other recent EIA positive premises in California. Broodmare and stud farms should build EIA testing into annual health calendars as a routine biosecurity measure.
Key Takeaways
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EIA has no cure and no U.S. vaccine, and infected horses remain carriers for life.
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The Coggins test is the standard screen, with positives always retested to exclude false results.
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A confirmed positive in California means lifetime quarantine 200 yards from other equids or humane euthanasia.
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EIA spreads through blood, including biting flies, shared needles and equipment, not casual pasture contact.
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California confirmed EIA positives across at least eight counties during 2026.
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Fly control and needle hygiene are the practical defences owners control.
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Equine Salt Therapy’s Ultisalt™ therapy offers a complementary, non-invasive welfare support option for practitioners and owners.
