| VETERINARY |
EQ UIN E HER PESV IR US- 1 AN ELUSIVE TARGET Neil Bryant
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Neil Bryant and Shutterstock
nfectious diseases are not uncommon in racehorses in training, breeding stock, and pleasure horses. Some of the more serious diseases can be financially devastating to the fin fi animal’s owners and to the equine industry on the whole. Viruses belonging to the herpesvir irus family cause some of the most well characterized equine infectious diseases, and the most problematic of these is equine herpesvir irus 1 (EHV-1; species Equid alphaherpesviirrus 1). EHV-1 is ubiquitous in most horse populations in the world. It is responsible for major economic and welfare problems causing respiratory disease, neurological disease (mainly seen in adult horses), and abortion and neonatal foal death in pregnant mares. This was
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TRAINERMAGAZINE.COM ISSUE 48
most notably highlighted by the multiple abortion outbreak recorded in Hertfordshire, England, between February and April 2016 in fully vaccinated animals (http://ww www. www w.aht.org.uk/cms-display/interimreport16-april2.html). Studies have determined that EHV-1 is a common cause of abortion. Occasional cases have also been linked to EHV-4 infection, but this is much rarer and doesn’t account for episodes of multiple abortion, as is seen occasionally wit ith EHV-1.
The virus
EHV-1 was fi first isolated from an equine abortion in fir the U.S. in the 1930s. At the time of fi first isolation fir the vets weren’t sure what it was, but they knew it was infectious. Subsequent genetic analysis much later led to the classifi fication of the vi fic virus in vir virus (family Herpesvi vir viridae), vir the genus Varicellovi