Equine Influenza: Highly Contagious Respiratory Virus
Equine influenza spreads rapidly and causes widespread outbreaks. Vaccination and biosecurity are essential for prevention.
Equine influenza is a highly contagious viral respiratory disease caused by influenza A virus (H7N7 and H3N8 subtypes). It spreads rapidly among unvaccinated horses, causing outbreaks that can shut down racing and showing operations. While rarely fatal, it causes significant economic loss and athletic setback.
Key Points
- Equine influenza is one of the most contagious diseases of horses
- The virus spreads via aerosol droplets up to 50 meters and on contaminated hands, clothing, and equipment
- Signs include sudden fever, dry cough, nasal discharge, and muscle soreness
- Most horses recover in 2-3 weeks, but performance may be affected for months
- Vaccination is the cornerstone of prevention; boosters every 6 months for high-risk horses
- Rest is critical — returning to work too early causes complications
How the Virus Spreads
Equine influenza spreads through respiratory droplets from coughing and sneezing. Direct contact with infected horses is the primary route. Indirect spread via hands, clothing, tack, brushes, and feed buckets is common. The virus survives on surfaces for hours to days. Infected horses shed virus for 7-10 days. Crowded conditions, transport stress, and poor ventilation increase transmission.
Vaccination and Prevention
Vaccination is the most effective preventive measure. Primary series: 2-3 doses starting at 6 months. Boosters every 6-12 months depending on risk — high-risk horses (racers, show horses, boarding stables) need 6-month intervals. Vaccinate at least 2 weeks before travel or competition. Combined vaccines protect against influenza, EHV, and tetanus. Biosecurity measures — quarantine new horses, don't share equipment, and practice hand hygiene — complement vaccination.
When to See a Vet Immediately
- Your horse has sudden fever, cough, and nasal discharge
- Multiple horses are affected simultaneously
- The horse was recently at a show, race, or boarding facility
- There's muscle soreness and reluctance to move
- Vaccination status is uncertain or overdue
How RVC Can Help
This article is for educational purposes only and does not replace professional veterinary advice. If your pet is showing any symptoms, please contact Royal Veterinary Center immediately at +853 6677 6611.