Centennial State News

Two horses in Colorado have tested positive for Equine Infectious Anemia (EIA), an incurable ailment affecting equine animals including horses, mules, and donkeys. The Colorado State Veterinarian’s Office reported the cases, explaining that both horse owners chose to euthanize the infected animals. The current risk to the general equine population in Colorado is deemed low.

The first case was detected in Douglas County on April 5 in a pregnant mare that had recently traveled to Colorado. Confirmatory tests were concluded on April 10 by the USDA National Veterinary Services Laboratory. This case is linked to a significant EIA outbreak associated with a Texas veterinary clinic in 2024. Poor hygiene practices were identified as the cause of disease transmission at the clinic. While investigations are still underway, no other horses in Colorado have been exposed.

A second horse was confirmed positive on April 9 in Jefferson County after routine testing at a veterinary clinic for a Certificate of Veterinary Inspection required pre-movement. The USDA National Veterinary Services Laboratory confirmed the diagnosis on April 15, initiating quarantine and testing for any potentially exposed horses.

Highlighting the essential nature of disease prevention, Colorado State Veterinarian Dr. Maggie Baldwin stated, “The confirmed transmission in the Texas outbreak highlights the importance of strict disease prevention practices and routine EIA testing.” She cautioned that neglecting sanitation protocols could lead to severe consequences, adding, “I encourage all Colorado veterinarians to review their practice’s sanitation protocols with their staff.”

Regular testing for EIA, known as the Coggins test, is advised for all horses. Additionally, a negative EIA test and a Certificate of Veterinary Inspection are necessary for inter-state movement of equines in the United States.

The Colorado Department of Agriculture (CDA) suggests that equestrian events such as shows, rodeos, and fairs require proof of a negative EIA test for entry, even if horses remain within the state, to prevent disease proliferation.

Equine Infectious Anemia is a viral disease transmitted through large biting insects or reusing needles and equipment among susceptible equines. Infected horses may be asymptomatic but can experience severe health issues, including fever, weakness, weight loss, anemia, and even death. EIA cannot be transmitted to humans, but infected animals must be quarantined indefinitely or euthanized.

For further details, individuals can refer to the USDA Equine Infectious Anemia website or the Colorado Department of Agriculture’s guidance on reportable diseases.