Third Piroplasmosis Horse Reported Missing

A third horse that tested positive for equine piroplasmosis was illegally removed from quarantine in June, stated a 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.  

In June Animal health officials confirmed equine piroplasmosis in Missouri after a horse formerly stabled at the Raytown Equestrian Park was hospitalized and found to be positive for the disease, setting off a foreign animal disease investigation. The stable, home to 64 equids, was placed under quarantine on June 6.

On June 17, someone removed two bay Quarter Horses that had been confirmed positive for causative organism Theileria equi from the Raytown quarantine. These horses have not been located (read more). Another five horses were euthanized June 18 with their owners' consent.

According to the June 26 OIE statement, a third positive horse was also illegally removed from quarantine in Kansas. A spokesman for the Animal and Plant Health Inspection Service said the Kansas horse was a gray mare that had originated from the Raytown premises.

Equine piroplasmosis is an infectious disease caused by either of two different protozoal parasites that attack the red blood cells. It is characterized by fever, anemia, weight loss, jaundice, and, in some cases, death. The case fatality rate can be up to 20% in naive horses (those which have never been exposed). The only treatment is a potent type of chemotherapy that can have serious side effects in some horses. United States officials have screened all imported horses for piroplasmosis for nearly 30 years.

The OIE report lists the source of the current cases as unknown or inconclusive, with notations for illegal movement of animals and sharing of needles.

The equids remaining at the index premises had re-tested negative for Theileria equi as of June 24. Additional test results were pending at the time of the report.

Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.