January 4, 2008
Study: Light-Colored Horses at Higher Risk of Dying from West Nile Virus 


Researchers at the Western College of Veterinary Medicine in Saskatchewan, Canada, recently published
a study indicating that light-colored horses diagnosed with West Nile virus (WNV) might be more 
likely to succumb to the disease than their darker counterparts.

Horses included in the study were divided into three groups based on coat color: dark (chestnut, bay, 
black, brown, and sorrel), light (gray, white, palomino, buckskin, and dun), or multicolored (roan, 
paint, pinto, and appaloosa).

Of the 124 horses diagnosed with WNV grouped according to coat color, dark-colored horses were most 
commonly infected (89 out of 124 cases, or 71.8%). However, the fatality rate was only 36% in the dark group, 
compared to 74% in light-colored horses.

"Our study found that light-colored horses were 4.4 times more likely to die or be euthanized than dark-colored 
horses," reported Tasha Epp, DVM, a co-author on this study.

There reason for this remains unknown, but the researchers suggested that immune response in horses might 
be genetically linked to coat color.

The study, "Factors associated with West Nile virus disease fatalities in horses," was published in the 
Canadian Veterinary Journal in November 2007.

 
Copyright:  Alberta Equestrian Federation
5/17/2008 : 3:43:58 AM