If you own a horse and live in any of the Western states, you’d be hard pressed to have not heard about this past week’s outbreak of EHV-1. While the threat of widespread infection is very real, the San Jose and South Bay areas are currently clear of diseased horses.
What you should know
- There are numerous strains of the Equine Herpes Virus, or EHV-1. The most common form, Equine Rhinopneumonitis,or Rhino, manifests as a respiratory disease. The current outbreak of EHV-1 is Equine Herpes Virus Myeloencephalopathy, a neurological form of the virus.
- EHV-1 is mainly spread through nasal secretions, horses touching nose-to-nose, and can be passed on contaminated tack, grooming equipment, handlers’ clothing, and shared water buckets or stalls. It is extremely contagious.
- Shed virus cannot spread much further than 50-100 feet.
- Most horses have been exposed to EHV-1 at some point in their lives and the virus lies dormant.
- It is suspected that the activated virus can be triggered by stress or competition, but no one knows for sure the exact cause of activation.
- There is no vaccine for the neurological strain, and no approved antiviral drugs for treatment.
- Treatment is available though through supportive means such as anti-inflammatory drugs, and IV fluids.
- Respiratory and neurologic symptoms can be caused by a number of other horse diseases (Equine Influenza, West Nile), and manifestation of these symptoms does not automatically mean a horse has contracted EHV-1.
- The virus poses no risks to humans.
What you should do
- Make sure you get your horses’ Rhino vaccinations updated if you haven’t yet this year. If it’s been a few months, check in with your vet to see if they recommend a booster, especially if you have higher risk horses such as young foals, pregnant mares, or older horses. The Rhino vaccination will not prevent the neurologic form of EHV-1, but it will boost immunity for the respiratory form which can help deter its progression to the neurologic. Horses that do not have the Rhino vaccination are at a much higher risk of contracting the neurologic form of EHV-1.
- Pay strict adherence to barn rules about quarantining.
- Avoid all unnecessary travel which includes taking your horses to shows, riding on public trails, petting unknown horses, and generally avoiding any activities where your horse is likely to come into contact with other horses.
- Don’t share any grooming tools, tack, water buckets or other equipment.
- If you suspect your horse has been exposed, monitor your horses’ temperature twice daily. Typically the first sign of infection is a fever spike of 101.5 or higher. If your horse spikes a fever, call your vet immediately.
- Watch for neurologic symptoms. These include ataxia, or paralysis of the hind limbs, as well as difficulty with urination or defecation, and a general lack of coordination.
- Stay in contact with your veterinarian and barn owners to stay abreast of the latest updates and quarantine regulations.
How this will impact your life
- Many smaller events and shows are being cancelled or postponed. As of today, the Western States Horse Expo is still scheduled to occur as planned, and will include the annual auction. Some people are choosing to keep their horses at home, or forego attendance entirely as a precaution.
- Many barns throughout California and other western states are instituting strict lockdown policies for the next three to four weeks. This includes no in or out horse traffic, including riding on public trails or with friends at neighboring barns.
- California state borders are still open to horse travel. Currently, only Colorado and Wyoming are requiring additional certification for equine entry.
- If you do need to transport your horse across state lines, it is a good idea to check with local and state officials for up-to-date regulations.
Why you shouldn’t panic
- While there is no cure for EHV-1, contraction of the virus is certainly not a death sentence. Quick action at the onset of symptoms, and supportive treatments can be very helpful with treating infected horses.
- As of last night, all confirmed cases were traced to horses attending a National Cutting Horse Association Championship at the beginning of May in Ogden, Utah. There are no reports of infected horses not in attendance at the competition. Unless your horses were in contact with one of those in the Ogden competition, more than likely they will be fine.
- So far there are no confirmed or suspected cases in Santa Clara County. California counties with confirmed EHV-1 cases are Amador, Glenn, Kern, Los Angeles, Napa, Placer, Plumas, and Stanislaus.
In summary, for the time being, keep your horses at home, keep your vet’s phone number close by, and keep watching here for updated information.
For extended information on the neurologic form of EVH-1, check out this USDA APHIS article.