What Is Coggins Disease in Horses?

Coggins is not a disease, but rather the test performed for equine infectious anemia virus (EIAV). Most horse owners are more familiar with the term 'Coggins' than the disease it tests for because state regulations require a negative Coggins certificate before a horse can participate in a show or be transported out of state. In some areas, a certificate is required before a horse can be sold. Tests must be repeated annually and in some states, every six months.

  1. Significance

    • Equine infectious anemia, also called swamp fever, is an infectious disease of horses that affects the immune system. It is spread by blood-sucking insects, most commonly horseflies, but can also be transmitted from one horse to another by improper use of syringes, dental floats or shared bits.

    History

    • The first records of EIAV were noted in the early 1840s. One of the worst epidemics took place in New Hampshire in the 1940s, when 77 horses died or were euthanized due to EIAV. In 1970, Dr. Leroy Coggins developed the first successful laboratory procedure for diagnosis of EIAV, hence the term Coggins test.

    Types

    • EIA can be described as acute, chronic and carrier. Acute EIAV occurs suddenly. The most common symptom is fever, and the diagnosis is often missed. Horses that survive the initial infection may have relapses of symptoms. This is described as chronic EIAV. Other horses may be asymptomatic but will have a positive Coggins and can transmit the EIAV to other equines.

    Features

    • Horses that contract acute EIAV usually die within a relatively short time. Horses with chronic EIAV may appear healthy most of the time but have recurring episodes of high fever (105 to 108 degrees F), loss of appetite, weight loss, swelling of legs and belly, hemorrhaging of mucous membranes and irregular heartbeat.

      Asymptomatic carriers seldom show any symptoms unless stressed.

    Considerations

    • There is no vaccine or cure for EIAV. The law governing treatment of horses with a positive Coggins requires euthanasia, sale for slaughter or lifetime quarantine of the animal a minimum of 200 yards away from all other equines, which is out of range for disease transmission.

    Warning

    • Owners of horses that have a positive Coggins have few choices for a final outcome. However, not testing is a poor solution. Horse owners can help protect their animals by keeping them away from untested horses.