West Nile Virus encephalomyelitis in horses: 46 cases (2001)

Abstract

Our findings were similar to those of previous WNV outbreaks in horses but provided additional clinical details from monitored hospitalized horses. Diagnostic testing is essential to diagnosis, treatment is supportive, and recovery rate of discharged ambulatory horses is < 100%.

Comparative Efficacies of Three Commercially Available Vaccines against West Nile Virus (WNV) in a Short-Duration Challenge Trial Involving an Equine WNV Encephalitis Model

“…In addition, horses in this study were evaluated very closely and several times per day postchallenge for clinical signs, allowing for the detection of slight changes from original baseline values that would not have been detected by owners or field veterinarians not associated intimately with baseline values. Epidemiological studies characterizing the outbreaks have reported a percentage of horses with appropriate vaccination histories that developed WNV disease (6,20). Although none of the vaccinated horses in this study fit the case criteria for West Nile virus encephalitis, the percentage of horses that developed mild clinical signs mirrors the findings of these outbreak studies.…”

Equine Risk Assessment for Insecticides Used in Adult Mosquito Management

“…And, of those horses that develop clinical signs of illness, the mortality rate is approximately 33% (Murgue et al 2001;Ostlund et al 2001;Trock et al 2001;Porter et al 2003;Weese et al 2003;Ward et al 2004Ward et al , 2006.…”

Incidence and effects of West Nile virus infection in vaccinated and unvaccinated horses in California

“…In 1999, WNV was first detected in North America in New York, and subsequently the virus spread throughout Canada, the USA, Mexico and the Caribbean [13,14,21]. Horses have been the mammalian species most impacted during the current epidemic of WNV infection in North America, with attendant high morbidity and mortality [20,22,[25][26][27][28]. WNV was not detected in California until July 2003, when the virus was identified in Culex tarsalis mosquitoes in the Imperial Valley of southeastern California [24].…”