Late-Term Abortion, Stillbirth, and Neonatal Foal Death in Kyrgyzstan: First Isolation of Equine Herpesvirus Type 1 in the Country

• Published in: Journal of equine veterinary science Vol. 51; pp. 46 - 53
• Main Authors: Akhmedzhanov, Maksat, Nurgaziev, Rysbek, Orozov, Jailobek, Moser, Irmgard, Osterrieder, Nikolaus, Damiani, Armando Mario
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-04-2017
• Subjects: Abortion; EHV-1; Kyrgyzstan; Mare; EHV-1; Mare; Abortion; Kyrgyzstan
• ISSN: 0737-0806; 1542-7412
• DOI: 10.1016/j.jevs.2016.12.008

Late-term abortion, stillbirth, and neonatal foal mortality (commonly referred to as late fetal losses [LFLs]) of unknown etiology are a serious concern for horse farmers and breeders in Kyrgyzstan. Therefore, we investigated major infectious causes of LFL, with a focus on viral agents, for the first time in the horse population in the country. A total of 221 sera and 149 nasal swabs taken from mares in farms with a history of LFL within 1 year of testing as well as tissue samples collected from 17 LFL cases were investigated. Serologic studies revealed that equine herpesvirus type 1 (EHV-1) and type 4 (EHV-4) were prevalent in the population, although positivity rates were low with neutralizing antibody titers of 1:4 to 1:32 (median 1:8) against both pathogens. High antibody titers in the range from 1:32 to 1:512 (median 1:256) against equine arteritis virus (EAV) were detected in mares on a single farm, whereas three mares from different farms tested positive for Dourine. Virus isolation and PCR investigations of nasal swabs did not suggest ongoing active infection with EHV-1, EHV-4, or EAV in the examined mares. Bacteriologic and virological examination of tissue samples taken from LFL cases revealed the presence of Escherichia coli and/or Streptococcus equi (subsp. zooepidemicus) in 35% of neonatal foal death cases, and EHV-1 was isolated from a late-term abortion case representing the first isolation of this important pathogen of horses in the country and, to the best of our knowledge, in Central Asia.
•Increased numbers of abortions are being reported to the veterinary authorities in Kyrgyzstan; therefore, an investigation is conducted.•Equine herpesvirus type 1 is isolated from the first time in the country and, to the best of our knowledge, in Central Asia.•Lack of evidence of viral involvement in 39 investigated small family-owned farms.