The Pennsylvania Department of Agriculture announced April 20 the quarantine of an equine barn in Halifax, in Dauphin County, after a horse at the barn tested positive for equine infectious anemia (EIA) on April 18.

There are 19 other horses quarantined on the premises as part of the quarantine order. The EIA-positive horse had a routine health check, which included a Coggins test for EIA, less than a week after the horse moved from another barn elsewhere in Dauphin County.

The horse was stabled previously at a farm in Williamstown, where another 13 horses are also under quarantine. The department is in the process of tracing the positive horse’s movement history.

The barns and horses are quarantined for at least 60 days. The quarantine can be lifted after the remaining horses are determined not to be infected.

Equine infectious anemia is a viral disease that attacks horses’ immune systems. The virus is transmitted through the exchange of body fluids from an infected to a noninfected animal, often by blood-feeding insects such as horseflies, and more rarely through the use of blood-contaminated instruments or needles.

Once an animal is infected with EIA, it is infected for life and can be a reservoir for the spread of disease. Obvious clinical signs of the disease include progressive loss of condition along with muscle weakness and poor stamina. An affected horse also could show fever, depression, and anemia.