Contagious Viral Disease
Kentucky researchers developed a test to determine if stallions are a long-term equine arteritis virus carrier.
It is The University of Kentucky Gluck Equine Research Center’s latest novel innovation. Faculty members developed the test to determine the genetic basis of a specific haplotype or a group of genes inherited from one parent.
Outbreaks of equine viral arteritis may result in significant economic losses to the equine industry. It may cause pregnancy loss in mares, death in young foals and establish a carrier state in stallions.
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 initially shed the virus in their semen following infection. Virus clearing from the reproductive tract usually happens within months following infection. Stallions possessing even one copy of the susceptible haplotype are at greater risk for becoming long-term shedders of EAV.
“Since surgical castration can be resorted to in stallions that are confirmed carriers of EAV, this test can help identify those horses that may spontaneously clear themselves of the virus, thus avoiding the loss of a valuable breeding animal,” said Kathryn Graves, director of the Genetic Testing at Gluck laboratory.
The test indicates horses with the susceptible haplotype and therefore are at higher risk for becoming carriers if infected with EAV. The implementation of appropriate management practices and vaccination can help bypass the risk of infection and becoming a carrier.
Researchers recommend vaccinating colts and stallions negative for antibodies to EAV.