What it is?

EAV is the virus behind equine viral arteritis (EVA). In many horses it can look like a routine “barn cold”-a few days of fever and runny noses-and then it’s gone. The catch is breeding: sexually mature stallions can become long-term shedders, passing the virus in semen even when they look perfectly fine. 

Why it matters?

Most adult horses recover, but the real-world impact is movement restrictions, disrupted training schedules, and (in the wrong circumstances) abortions in pregnant mares. And clinically, EVA can’t be reliably distinguished from other equine respiratory/systemic diseases without lab confirmation-so guessing is how yards get burned. 

How it spreads?

There are two main routes. First, respiratory spread: close contact with infected secretions, especially during the acute febrile stage. Second, venereal spread: infected semen through live cover or AI. In mixed groups, outbreaks often start “the usual way” (respiratory), while longer-term circulation is typically driven by carrier stallions. 

What you might see?

Signs range from none to obvious: fever, lethargy, nasal discharge, conjunctivitis, and swelling (edema) of the limbs, belly line, sheath, or scrotum. Some horses show urticaria-like skin lesions. In outbreaks among naïve animals, abortions can occur, which is why breeding operations treat EAV as a priority pathogen.

Diagnosis (keep it simple)

When you need a yes/no answer for active infection, RT-qPCR is the most reliable workhorse-fast and sensitive on the right samples (nasal swab/whole blood). For in-vitro workflows, Vitrosens Biyoteknoloji A.Ş. lists an EAV Detection Kit with product code VVE01 for detecting Equine Arteritis Virus from equine nasal swab samples; stick to the kit IFU and interpret results with clinical context and biosecurity decisions. 

Control and prevention

If EAV is suspected, don’t gamble: isolate, pause breeding movements, and test strategically (especially stallions and semen). Quarantine new arrivals, separate by risk, and keep vaccination/testing policies aligned with your farm’s movement and breeding goals. 

References

1. WOAH (World Organisation for Animal Health). Equine Viral Arteritis (Terrestrial Manual chapter). https://www.woah.org/fileadmin/Home/eng/Health_standards/tahm/3.05.10_EVA.pdf
2. Merck Veterinary Manual. Equine Viral Arteritis. https://www.merckvetmanual.com/respiratory-system/respiratory-diseases-of-horses/equine-viral-arter…
3. CFSPH (Iowa State University). Equine Viral Arteritis factsheet. https://www.cfsph.iastate.edu/Factsheets/pdfs/equine_viral_arteritis.pdf