Detecting PHF in Oklahoma; Behind the Headlines

The recent confirmation of Potomac horse fever (PHF) in an Oklahoma horse was possible because of relatively new–and inexpensive–testing techniques that help speed diagnose of the disease. This allows horse owners to be alerted

Share
Favorite
Close

No account yet? Register

ADVERTISEMENT

The recent confirmation of Potomac horse fever (PHF) in an Oklahoma horse was possible because of relatively new–and inexpensive–testing techniques that help speed diagnose of the disease. This allows horse owners to be alerted to the active presence of the disease’s causative agent in their area. Recognition of the disease in areas unused to seeing PHF is important. This burden falls to treating veterinarians, horse owners, and diagnostic laboratory officials who take or request blood or tissue samples from horses with clinical signs of PHF.


The Lucy Whitier Core Molecular Laboratory at the University of California, Davis (UC Davis) School of Veterinary Medicine, reported the Oklahoma equine case on Aug. 22 after tests were completed that day on blood and feces.


Potomac horse fever’s causative agent, the bacterium Neorickettsia risticii, has been linked to parasites of freshwater snails. The parasites are called cercariae, and they also infect the larvae of mayflies and caddis flies in fresh water. When the infected fly larvae mature into infected adult flies, they can be ingested by horses inadvertently consuming the insects while grazing or eating feedstuffs.


John Madigan, DVM, MS, Dipl. ACVIM, of UC Davis, has been involved in PHF research for nearly 10 years. He was part of the research group that linked caddis flies and mayflies to the life cycle of PHF in 2000, demonstrating that they carry the infectious agent. That group also did the first experimental reproduction of the disease by feeding horses infected caddis flies. Researchers at The Ohio State University have since reproduced the UC Davis study and confirmed the initial finding of transmission by ingestion of insects

Create a free account with TheHorse.com to view this content.

TheHorse.com is home to thousands of free articles about horse health care. In order to access some of our exclusive free content, you must be signed into TheHorse.com.

Start your free account today!

Already have an account?
and continue reading.

Share

Written by:

The Horse: Your Guide To Equine Health Care is an equine publication providing the latest news and information on the health, care, welfare, and management of all equids.

Related Articles

Stay on top of the most recent Horse Health news with

FREE weekly newsletters from TheHorse.com

Sponsored Content

Weekly Poll

sponsored by:

What lameness issues has your horse experienced? Select all that apply.
231 votes · 458 answers

Readers’ Most Popular

Sign In

Don’t have an account? Register for a FREE account here.

Need to update your account?

You need to be logged in to fill out this form

Create a free account with TheHorse.com!