Equine Herpes Virus 1

It’s been big news in the US in the last few months, so the big question is – could the same thing happen here in Australia?

Well  according to well known and respected Veterinarian Dr Stuart D. Keller BVSc MACVSc, from the Tamworth Equine Vetinary Centre (TEVC), the short answer is probably not. But the long answer is EHV1 is already here. The virus is nothing new in Australia and manifests itself here as what is described as Viral abortion in broodmares.

The virus is very easily and quickly transmitted and generally happens in small clusters, an infected mare will abort her fetus and other broodmares in the same group, will sniff and lick the foetus and catch the virus. However with the Australian strain the neurological symptoms that our American counterparts have experienced happen less frequently .

Dr Keller says, ” In Australia our horses are generally kept in a more expansive environment, so we don’t see the virus transmitted to such an extent as was experienced in the recent US outbreak. The horses over there are generally kept close together in barns where the virus can be quickly and easily spread through the expulsion of mucous and the likes. Here there is generally more space between our horses therefore the lower the risk of contamination.”

Once a mare is infected with EHV1 and recovers the virus can remain dormant in her system and reappear without warning.  “It sits as a latent infection, and for example if the mare becomes stressed it can resume again, the virus can manifest itself further down the track without warning “.

There are actually four strains of the virus here in Australia, EVH1, EVH2, EVH3, and EVH4. EVH1 is the virus we have just talked about, EVH2 and EVH3 are quite insignificant and EVH4 is more like a respiratory infection.

There is a vaccine available, “Duvaxin” and it is used for the prevention of EVH1 and EVH4, it’s used narrowly and is recommended as a course of treatment if you are sending your broodmare to a farm that has a history of EVH1 or EVH4.

“Probably our most significant outbreak of recent times was the Virus that spread through the Murray River Basin a few months back – The Flavi Virus. This virus is transmitted by biting insects, it actually killed a few horses, and although we couldn’t prove it we suspect one if it’s victims was a Cutting Horse in the area”.