01/27/2026
Newish disease for horse owners to be aware of…
Have you heard of Equine Parvovirus-Hepatitis (EqPV-H)? Here's some important information to know about the disease.
How Does It Spread?
• The preponderance of evidence currently suggests direct contact and nasal transmission as the most likely major route of horizontal transmission.
• The virus is shed in nasal secretions, saliva, and f***s of recently infected horses.
• Direct contact or a high burden of biting flies is likely required for transmission.
• In rare situations, it can also be transmitted through biologic products (these are special treatments like plasma, serum, or antitoxins).
• Chronic carriers do not appear to be contagious.
What Should You Watch For?
⚠️ At this time, it is unknown what causes some horses to develop the clinical form. While most horses stay healthy, a small number may develop:
• Tiredness or depression
• Not wanting to eat
• Yellowing of the eyes or gums (jaundice)
• Dark urine
• Unusual behavior or trouble walking (in severe cases)
What Can You Do?
• Watch for any signs of liver trouble, especially if your horse has recently received biologic products.
• Maintain a clean environment and avoid sharing needles or equipment between horses.
• If your horse seems unwell, contact your veterinarian promptly.
Key Takeaways:
• Although we just discovered it, this is not a new virus or new emerging threat to horses. There's no need to panic as some 15-20% of horses are already infected.
• Horses become long-term carriers, so they can test positive for years without any current disease or risk of developing liver disease.
• Horses in early infection and during liver disease are contagious for a few months.
• Carriers with low viral load do NOT appear to be contagious and we don't recommend isolation based on current knowledge.
• Because of the carrier status, a positive test for parvovirus does not mean it is causing disease, other causes of liver disease need to be thoroughly ruled out.
• There’s currently no vaccine for EqPV-H, but the risk of serious illness is low for most horses.
As always, if you have concerns about your specific equine, contact your veterinarian.
📸 Dr. Mason C. Jager (this photo shows a liver biopsy)
