Potomac Horse Fever: Neorickettsia (Ehrlichia) risticii
  by Robert N. Oglesby DVM

In 1979, a disease characterized by fever and diarrhea, during the hot months of the year was recognized in the Potomac river basin. It resembled other causes of diarrhea, but the inability to isolate known causes started veterinarians looking elsewhere. A bacteria-like organism was isolated from the infected horses blood and cells of the large colon. The ricketssial organism Neorickettsia (Ehrlichia) risticii was determined to be the cause of the disease. Since that time the organism has been identified serologically in 43 states of the US, the Canadian provinces of Saskatchewan Ontario and Nova Scotia, France, Italy, Venezuela, Brazil, Uganda, India, and Australia. However the organism has only been isolated in the US from 13 states (CA, IL, IN, KY, MD, MI, NY, NJ, OH, OR, PA, TX, VA), 3 Canadian Provinces (NS, ON, AL), South America, The Netherlands, and France. This article discusses transmission, clinical signs, diagnosis, treatment and prognosis. Also vaccination and other prevention is discussed.

You have just read the introduction to one of our nearly 800 articles on horse care, diseases, and training. It includes a description of the contents of the unabridged version. As a guest you can access this article two different ways: either purchase the article or become a member and take advantage of all the benefits Horseadvice.com has to offer. Check out our Membership Drive Discount below but hurry. This is for a limited time!