[Kenike]

This is happening in my area and has me on edge as there are a lot of horses around here. The part that concerns me is all reports state they were found dead or euthanized from symptoms of an "unknown illness."

Yes, the prison has a quarantine in place. Yes, necropsies are being performed. No, foul play is not a factor.

I have already asked my vet to find out what she can so I can have a plan (I hope from farm to farm currently), but I just hope there's not some massive outbreak of EHV-1, or something, going on...

http://www.koaa.com/news/wild-horses...n-city-prison/ (I only chose to link one story, but there are plenty posted on the net)

[BasqueMom]

Keep us posted....any more info yet?

[Simkie]

Yikes. Very odd. Presumably the horses went downhill very quickly to just be found dead in the pen?

EHV-1 certainly comes to mind. Perhaps rabies? I know we've seen a huge uptick this year. I wonder if these horses were vaccinated, since we have not really had to vaccinate here until this year or last...

Or botulism, as they're feeding hay from another source as a precaution?

[furlong47]

I can't think of anything that would kill massive amounts all at once, that quickly, except maybe some kind of poisoning (intentional or via some natural source like contaminated feed/water). Unless these horses aren't checked that regularly and it could have spread over time. Even EHV-1 or Rabies you should probably see some symptoms first before they all just keel over.

[Kenike]

They're testing the hay and water, too. I don't know if this was a newer herd, which would certainly make it more difficult to pinpoint illness versus stress...a little. No matter what, they locked that place down tight immediately (no pun intended), which speaks highly to how cognizant they are about communicable diseases. I applaud them for that!

I will share as I learn more, but if anyone else comes up with anything, please share!

[ReSomething]

The first thing that popped into mind is the case of the polo ponies that were fed improperly mixed supplements - but mustangs aren't likely to be getting special supplements! I feel very badly for the inmates as well,as far as I know they work hard with the animals and it's positive work.

Hope they discover the root cause and quickly.

[Plumcreek]

I just sent a note to my vet to see if any info is being sent out.

[Kenike]

Well, Cass called and said the initial report is out. Looks like someone screwed up and didn't pay attention to their hay field. Or maybe should have checked their hay source better?

There was whirled milkweed in the hay. While I'm grateful there's no need to worry about the threat of communicable disease with this case, I feel so bad those animals essentially were inadvertently poisoned.

I've found two articles to this point, but I'm sure more will come out. Here's from my local paper:
http://m.chieftain.com/news/region/w...9bb2963f4.html

[IdahoRider]

There was whirled milkweed in the hay.

Thank you for the update. I wondered if they had been able to establish a cause.
Sheilah