West Nile Virus
•Caused by a
virus
•Spread via
mosquitoes
•Throughout the
US
–2003 – over 4,000 cases in
horses
–2002 – over 14,000 cases
in horses
•Fatality-30%,
40% may have lasting deficits
•**Horses over 18 years had a 2.8X greater likelihood of dying or being euthanatized