St. Croix County horse contracts West Nile Virus; Wisconsin horse owners urged to vaccinate
August 18, 2014
St. Croix County horse
contracts West Nile Virus; Wisconsin horse owners urged to vaccinate (PDF)
Cline, 608-224-5005 or Jim Dick, Communications Director, 608-224-5020
MADISON – An unvaccinated St. Croix County mare is the first in
Wisconsin to contract West Nile Virus (WNV), prompting a reminder to horse owners
to vaccinate their animals against the virus and Eastern equine encephalitis
(EEE), two mosquito-borne diseases that together have stricken hundreds of horses
in Wisconsin since 2001. The 4½-year-old
quarter horse is recovering after being treated by a veterinarian.
cooler, wetter spring delayed a mosquito outbreak in
parts of the state, but now that things are heating up it creates the perfect
breeding environment for mosquitos,” says State Veterinarian Dr. Paul
McGraw of the Wisconsin Department of Agriculture, Trade and Consumer
Protection. “Cases of EEE have now emerged in southern states and now WNV has
been detected in a horse in Wisconsin."
Horses require two doses of the vaccination initially, and then
boosters at least annually. "We recommend working with your veterinarian,
so you get the best plan for your horse and advice about additional boosters
later in the season," McGraw says.
Both WNV and EEE are caused by viruses transmitted by mosquitoes,
and both may cause encephalitis, or inflammation of the brain. EEE kills about
90 percent of horses that it strikes, and WNV kills in more than a third of all
equine cases. Symptoms are similar for both diseases: depression, appetite
loss, drooping eyelids and lower lip, fever, weakness, twitching, paralysis or
lack of coordination, aimless wandering, circling and blindness.
Neither of the viruses is contagious between horses. While
humans can become infected by both WNV and EEE, it does not pass between people
and horses. Mosquitos biting warm-blooded animals is the only method of
Besides vaccination, McGraw recommends taking other steps to
limit horse exposure to mosquitoes:
- Remove items from surrounding property that
could collect stagnant water such as old tires, tin cans, plastic containers.
- Keep rain gutters clean and draining properly.
- Clean and chlorinate swimming pools, outdoor
saunas and hot tubs, and drain water from pool covers.
- Turn wading pools and wheelbarrows upside down
when not in use.
- Empty and replace water in birdbaths at least
once a week.
- Consider keeping horses in the barn from dusk to
dawn, when mosquitoes are most active.