Piroplasmosis Found in New Mexico Horses

As part of a racetrack screening program, three New Mexico horses have been identified as infected with Theileria equi, a causative agent for equine piroplasmosis. These infections are noteworthy as these horses are not epidemiologically linked to those involved in a larger ongoing investigation centered on horses from a South Texas ranch. Information on the new cases, and an update on the Texas investigation, was included in a Dec. 24 report issued to the World Organization for Animal Health (Office International des Epizooties, or OIE) by John Clifford, DVM, deputy administrator of the USDA's Animal and Plant Health Inspection Service. See the report. The positive New Mexico horses did not show any clinical signs of disease. Preliminary results of the investigation indicate that the transmission of the organism might have resulted from management practices (use of shared needles or substances between horses) rather than by a tick vector, the OIE report noted. More than 1,300 New Mexico horses have been tested via the screening program...read more