Researchers at the University of Kentucky (UK) Gluck Equine Research Center have developed a novel test to determine the likelihood of long-term equine arteritis virus (EAV) carrier state in stallions.

Gluck Center faculty members Udeni Balasuriya, BVSc, MS, PhD; Ernie Bailey, PhD; and Peter Timoney, MVB, PhD, FRCVS, Frederick Van Lennep Chair in Equine Veterinary Science, created the test for the genetic basis for a specific haplotype, a group of genes inherited from one parent. Their work was funded by a USDA Agriculture and Food Research Initiative grant.

Outbreaks of equine viral arteritis, which is caused by the virus, can result in significant economic losses to the equine industry due to pregnancy loss in mares, death in young foals, and establishment of the carrier state in stallions. The virus is maintained in the equine population between breeding seasons by persisting in the carrier stallion.

“It is gratifying to see how Drs. Balasuriya and Bailey’s work has led not only to a better understanding of the origin and development of this important disease, but also to a new test that can be used to identify those animals at risk for persistent infection,” said David Horohov, PhD, chair of the Department of Veterinary Science, director of the Gluck Equine Research Center and Jes E. and Clementine M. Schlaikjer Endowed Chair.

Stallions possessing the susceptible haplotype, consisting of four specific nucleotide changes in the CXCL16 gene, are more likely to remain long-term carriers of the virus in their reproductive tract than horses that possess the resistant haplotype. Stallions that are resistant and initially shed the virus in the