Tennessee Cases Increase

Potomac horse fever (PHF) probably has been endemic in the Western Hemisphere as long as horses have inhabited the region—perhaps even since the prehistoric era–and it’s here to stay. As awareness of the disease increases, so does the need to remain vigilant in managing horses to reduce the incidence, and severity, of cases.

PHF is also quite likely under diagnosed. In summer and fall of 2006, the University of Tennessee (UT) College of Veterinary Medicine tested 55 horses with clinical signs of PHF and found the incidence of cases to be 20% for the area, which includes most of East Tennessee. “It’s likely that many more horses had PHF in our area, but had mild signs or were not tested and just treated by our local veterinarians,” said UT’s Frank M. Andrews, DVM, MS, Dipl. ACVIM, professor and section chief of Large Animal Medicine.

Understanding the nature of Neorickettsia risticii–the organism that causes PHF–is key to managing the disease said Yasuko Rikihisa, PhD, a professor in the Department of Veterinary Biosciences at The Ohio State University (OSU)