Rhinopneumonitis, caused by equine herpesvirus (EHV), is a serious viral disease with multiple strains. EHV-1 and EHV-4 are the most concerning—EHV-4 primarily affects the respiratory system, while EHV-1 can cause respiratory signs, neurological issues, and even abortion in pregnant mares.
How EHV Spreads
- Direct contact with infected horses or bodily fluids
- Aerosol transmission through coughing or sneezing
- Shared equipment, stalls, tack, or handlers
- Stressful events like travel or competition that trigger viral shedding
Symptoms of Rhinopneumonitis
- Fever
- Nasal discharge and coughing
- Swollen lymph nodes
- Incoordination, hind limb weakness (neurologic form)
- Late-term abortion in pregnant mares
Treatment & Management
- Immediate isolation of affected horses
- Veterinary diagnosis and supportive care
- Minimize stress and maintain hydration
- Careful biosecurity and disinfection of equipment and facilities
- Long-term monitoring of exposed horses
Prevention Tips
- Vaccinate regularly against EHV-1 and EHV-4 per vet recommendations
- Quarantine new horses for at least 21 days
- Implement strict hygiene practices in barns and trailers
- Avoid nose-to-nose contact at shows and events
Why It Matters
EHV outbreaks can spread quickly and lead to long-term consequences, especially in breeding or performance barns. Proactive vaccination, smart quarantine protocols, and vigilant biosecurity are the best defenses against this invisible threat.