Locoweeds cause locoism, a disease state resulting from chronic neurological damage. In the Old World, native plants causing locoism have not been reported. In mule deer, clinical signs of locoism are similar to chronic wasting disease. Horses are very susceptible to the poisoning, and do not recover from locoism. In cattle at high altitude, complications of locoism can include congestive heart failure. In Argentina, locoism ("locoismo") was first reported in 2000. The first report of locoism in South America, involving "Astragalus pehuenches", was published in 2000.