Twenty-one horses stabled at a Beirut, Lebanon, racetrack have been euthanized after two of them tested positive for glanders, according to a report from the International Society for Infectious Diseases (ISID).

Glanders is caused by the bacteria Burkholderia (Pseudomonas) mallei. The contagious disease is characterized by nodules, abscesses, and ulcers in the respiratory tract and skin. Affected horses can die within a few days. The disease has also been known to spread to humans through contact with affected horses and can be fatal in people.

The report indicated that when two horses stabled at the Hippodrome racetrack recently imported from Syria began showing clinical signs of the disease, the entire stable was quarantined. Samples were taken from the horses and sent to a German laboratory to be tested for glanders; however, before the test results could be returned, other horses in the stable began showing signs consistent with glanders.

As a result, 21 horses were euthanized as a precautionary measure to keep the disease from spreading