MANHATTAN — Start thinking
now about protecting yourself and your horse from West Nile virus, says a Kansas
State University veterinarian.
Beth Davis, professor and head
of the equine medicine and surgery section at the College of Veterinary
Medicine's Veterinary Health Center, says there was an increase in Equine West
Nile virus cases in 2013. Summer 2014 is expected to have similar weather
patterns to summer 2013, so the risk of infections is just as high.
"We look to species
like horses to help give us some insight into how likely humans are to have
problems with the virus, but it's important to recognize that these sort of
weather patterns create a high risk for mosquitoes to transmit the disease not
only to horses, but also to potentially make humans sick," Davis said.
West Nile is an
encephalitic disease, which means it causes inflammation of the central nervous
system, specifically around the brain. It's a virally induced disease that is
transferred to horses and humans through mosquito bites from infected
mosquitoes. So far, eight states have reported West Nile virus infections in
mosquitoes, birds or veterinary animals. Mississippi has reported one human
case. Davis says the peak season for infection is mid to late summer, during the
warmer months. That's why it's important to start prevention methods now to be
protected by July.
West Nile virus is a core vaccine
for horses, recommended by the American Association of Equine Practitioners. Four
U.S. Department of Agriculture-licensed equine vaccines are available. Initial
vaccination requires a series of two to three vaccines, depending on the age of
the horse, and is then followed by annual boosters. Vaccine efficacy depends on
horse owners working with their veterinarians to establish proper protocols,
Another protection tip is
to eliminate all sources of standing water, which are breeding grounds for
"Eliminate things like
old tires, boats with tarps on them and rain gutters that may hold water,"
Davis said. "Birdbaths are areas where there is going to be standing water,
so clean them at least once a week. For other areas that you can't eliminate standing
water, like water troughs for livestock, put mosquito-eating fish in the tanks.
Minnows and goldfish will eat any of the eggs that have been laid by mosquitoes
and will minimize the mosquito replication."
The onset of clinical signs
for Equine West Nile virus is often sudden, with the progression occurring over
the following two to four days.
"Clinical signs of
West Nile virus can vary quite a bit in horses," Davis said. "Mild forms
of it may be a fever or a change in attitude for a few days. Most commonly, we do
see it progress to where the horse has neurological signs, which could be a
quite dramatic change in temperament or behavior. They may have a period where
they're not eating properly or they seem like they're not quite with it. Also,
they may experience changes in the nerves and control function in their head,
in things like eye movement and their ability to chew and swallow properly. We
may see dramatic changes in their gait, such as stumbling or being
If you suspect your horse has been infected with West Nile
virus, call a veterinarian immediately. You can contact the Veterinary Health
Center at 785-532-5700.