The name is deceiving,
but Potomac horse fever (PHF) is not just a concern for horses
near the Potomac River. Cases have been found across most
of the United States.1 Knowing the key signs of PHF and watching
carefully for them can help alert owners to protect other
horses at risk for infection.
“Every veterinarian and horse owner worries
about laminitis and colic. These could be classic signs of
PHF in the right context,” says Frank Hurtig, DVM, MBA, Director,
Veterinary Services. “Recognizing the signs of disease offers
a cue for quick PHF testing, and examination for other disease
concerns. Timely vaccination of horses in the area can help
prevent against additional cases of PHF.”
Some of the most commonly occurring signs
of PHF are:1
Fever
Colic
Diarrhea
Above signs, followed by laminitis
Abortion in pregnant mares
Up to 30% of PHF-infected horses die,1
and laminitis may continue even after other signs have stopped.
If a PHF case is located, all the horses in the area may be
at risk for infection, Dr. Hurtig warns.
PHF commonly occurs near bodies of water during
mid- to late-summer.1 However, it has been found in nontraditional
areas as remote as northern Wyoming.2 PHF has a complex life
cycle in which Neorickettsia risticii infect freshwater snails
containing flukes. Then, N. risticii is transferred to aquatic
insects such as caddisflies and mayflies. Horses become infected
after eating grass, feed or water containing these insects.1
Draining water and other management practices
can help reduce the risk of PHF transmission.1 To help prevent
against the most severe complications of the disease, Dr.
Hurtig recommends vaccination.
“Vaccination seems like a simple investment
when there is a possibility of colic, laminitis or even death,”
Dr. Hurtig says. “In recent years, PHF cases appeared in several
nontraditional states. That makes it a real concern for horses
in all areas of the country.”
In an efficacy trial, POTOMAVAC™ from Merial
protected 86% of horses from clinical disease.3 POTOMAVAC
is proven safe for horses as young as 3 months and is demonstrated
safe for pregnant mares. Plus, it is available as Equine POTOMAVAC
+ IMRAB® to help protect against both PHF and rabies.
Merial is a world-leading, innovation-driven
animal health company, providing a comprehensive range of
products to enhance the health, well-being and performance
of a wide range of animals. Merial employs approximately 5,000
people and operates in more than 150 countries worldwide.
Its 2007 sales were nearly $2.5 billion. Merial Limited is
a joint venture between Merck & Co., Inc. and sanofi-aventis.
For more information, please see www.merial.com.
