The World Organization for Animal Health reported on Oct. 21 an outbreak of equine piroplasmosis in Kleberg, Texas. The last reported occurrence was in August. Equine piroplasmosis (Theileria equi) is a tick-borne disease that affects horses, donkeys, mules and zebras. The disease is primarily transmitted via tick bites, although it has been spread mechanically from animal to animal by contaminated needles, according to the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service. The disease is not endemic to the United States; native tick species do not currently carry the parasites that cause the disease, according to APHIS. The source of the most recent outbreak was deemed “unknown or inconclusive.” APHIS and the Texas Animal Health Commission are conducting a comprehensive epidemiological investigation of the event, which started on Oct. 2 when a 7-year-old quarter horse mare was presented ill to a local veterinary hospital. A blood-borne pathogen was subsequently suspected and the horse was placed in isolation and initial diagnostic samples taken. The horse tested positive for equine piroplasmosis on Oct. 12. Thirty-one other horses epidemiologically linked with the affected animal were tested the following day. All tested positive. A quarantine was placed on the 128 horses on the premises. The additional 96 horses were tested for the disease on Oct. 19. Results are pending. The tick investigation on the premises is continuing and preliminary results of tick testing/speciation are also pending. OIE said that weekly follow-up reports will be submitted. Click here for details. <HOME>