05/03/2021
Important information following the EHV-1 outbreak currently going on in Valencia, Spain where the Sunshine Tour has been going ahead.
If you have any concerns, quarantine horses and halt movement to and from the yard.
This is a post that I first published just over a year ago, when I was arguing that all horses in Hampshire should go into a 2-3 week lockdown, following an EHV outbreak (including deaths) at a local competition centre and large livery yard. Now there is a huge outbreak on the continent, with horses travelling back to the U.K.
Swabs often come back negative for EHV, especially when the horse has started to develop an antibody response; I had negative swabs from a very sick horse, who very clearly showed an antibody response in his bloods.
PLEASE do the responsible thing and quarantine ALL horses on your yard if you either have recently come from overseas, or suspect EHV. I was told I was over reacting last time. I wasn’t.
Feel free to share.
*** EHV-1 Quick Facts ***
- Equine Herpes Virus 1
- Vaccination possible but NOT in the face of an outbreak and the vaccination does not protect against the neurological form (EHM)
- Vaccination of horses if they are currently incubating the virus, can increase the risk of developing EHM.
- Vaccination will however likely reduce viral shedding, at least of the respiratory form, which may precede the neurological form.
- EHM - Equine Herpes Myeloencephalopathy
- There is no way to predict which horses will develop EHM in an EHV outbreak
- The Influenza vaccination does NOT protect against EHV
- EHV-1 can cause respiratory problems, abortion, and neurological problems (EHM)
- Horses are often pyrexic (have a high temperature - >38.5)
- EHV is passed via direct and indirect transmission. This means airborne via nasal droplets, and via people/fences etc
- Almost all horses carry EHV-1, but it generally remains latent (inactive) until times of stress, such as travelling long distances/moving yards.
- There is no current test to determine if a horse is a carrier, as when the virus is latent, it is not shedding.
- The virus can live for seven days outside of the horse’s body (on bedding/rugs etc), and even for up to one month in perfect conditions.
- Most disinfectants will easily kill the virus.
- After infection, the INCUBATION period may be as short as 24 hours, but is typically around 4-6 days. It has also been known to be as long as 2 weeks.
- With the neurological form, the only other clinical sign is a high temperature. The onset of neurological signs is rapid, reaching peak intensity within 48 hours.
- Horses appear uncoordinated/weak/lethargic, and may have a head tilt or support themselves on stable walls. If a horse goes down with EHM, it is often difficult to get them back up.
- There are no cures once the virus has taken hold, but a couple of novel treatments have been used in the USA and I will be starting my client’s pyrexic horses on them tomorrow. These are not guaranteed to work or help.
- If you have been close to an outbreak recently, contact your vet to ask how best to proceed. At the very least you should have any exposed horse in isolation and be taking twice daily temperatures for 2 weeks. The whole of your yard should not be going out hacking or to other venues to compete, until the horses that were at that venue, have been tested clear. A nasal swab 6/7 days after you were there is advisable, but speak to your own Vet.
- If there are clinical cases on a yard, the yard should be on lock down for 28 days following the last clinical sign, to ensure no more cases appear.
I am still out working and have typed this in a rush inbetween calls due to the amount of messages I’ve had asking for more information.
Please can I ask that you speak to your own vet if at all concerned.
