Since
1999,
thousands
of
cases
of
equine
WNV
encephalomyelitis
reported
in
U.S.,
with
30-40%
fatality
rate.
Low
incidence
doesn't
negate
the
risk
of
West
Nile
virus
in
horses.
1999
West
Nile
virus
first
diagnosed
in
U.S.
horses
West
Nile
virus
is
an
endemic
in
all
areas
of
North
America.
Incubation
period
in
horses
is
3-15
days.
Stupor
Behavioral
changes
Difficulty
rising
Apprehension
Limb
weakness
Death
Fever
Muscle
fasciculation/
twitching
Blindness
Depression
Recumbency
Muzzle
tremors
Droopy
lip
Ataxia
Partial
paralysis
Teeth
grinding
Convulsions
of
horses
that
survive
acute
illness
experience
residual
effects
such
as
gait
and
behavioral
abnormalities.
40%
LESS
SEVERE
MOST
SEVERE
Clinical
signs
may
include:
