Eight cases of equine infectious anemia (EIA) have been discovered in Montana in 2000, according to officials from the stateâs Department of Livestock (DoL). All of the infected horses are on or traced from the Tehinnah Ranch in Melrose, Mont.

EIA is an incurable viral disease which is spread via infected blood. Montana law and federal regulations require that EIA-infected animals are quarantined 200 yards from other equids, sold only for slaughter, or euthanized.

The initial quarantine was made for one EIA-positive horse Jan. 31, and a quarantine for the farm has been ongoing. Since then, the original horse and one other horse traced back to the herd have been euthanized, and six other positives remain under permanent quarantine on the Tehinnah Ranch.

Since 1979, a total of 167 cases of EIA have been diagnosed in Montana. The high was in 1980, when 37 cases were diagnosed, followed by 21 cases in 1981, and 16 cases in 1991. At least one horse has been diagnosed with EIA in Montana every year since 1979. A negative Coggins test is required when a horse is imported into Montana, or shipped from Montana to another state. Mandatory EIA testing is not required for equids which reside in Montana. Some shows, sales, or other events require a negative Coggins test for horses to participate. Although this policy is strongly recommended by the Department of Livestock, it is not a state requirement