Join Date: Jan 2012
Location: Calgary, AB, Canada
That sounds like only half the story.
As Foxhunter says, EHV-1 is very prevalent in the horse population. It can manifest with respiratory signs (Rhino), abortions, or neurological signs. There is an indication that a certain point mutation has a higher incidence of causing neurological signs, but other strains can too, I.e. That mutation is not necessarily needed to cause neurol. Signs.
The virus - like Herpes in humans - goes into latency, which means the horse is infected, and then the virus "retreats" into certain cells. In that state, it will most likely be possible to detect antibodies in the horse, but the virus itself cannot be detected. It can resurface, esp in periods of stress (like a cold sore in humans), and the animal can shed again.
Vaccination does not prevent infection or shedding, but only reduces the clinical manifestation of Rhino, and to a debatable degree. Abortions (Pneumabort vaccine).
"Diagnosed with EHV-1" can mean many things. It is very common that horses have antibodies. It is also not uncommon for a horse to shed virus in a stressful situation.
If however a horse already has neurological signs (which I am suspecting was the cade with this mare), the prognosis is poor.
So girl 1, the owner, would very likely only prolong the suffering of the horse by hiding the diagnosis. Not very smart.
Not sure what the rules for reporting EHV in your state are, but chances are that not much would have been done apart from separating / quarantining the horse and good hygiene (i.e. No swapping water buckets etc). As far as I know, you're not actually required to put a neurological horse down.
I know that EHV-1 is scary, but there is not much more to do than keep good hygiene and keep the horses in a good, healthy condition.
Last edited by Regula; 06-12-2013 at 08:52 AM.