Ooh no. Poor pony! It swept through our barn about 7 years ago, and it was awful. It wasn't worth quarantining any one horse, because we figure someone had touched a horse with strangles and then came to visit horses at our barn.
Lots of compresses for their necks, and keep a close eye out for signs of strangles in any other horse at your barn.
I can't remember exactly, but I think we were treating horses at the barn for a few months... luckily my horse at the time didn't get it too badly.
I think it stays dormant for a while too? I have no idea how long, or I might be completely off base..?
Yeah, there's a ton of horses to watch out for. She goes out on the pasture at night with about 30 or so horses. So for now she's stuck in her stall until she's better. I feel so bad for her. I wish there was somewhere she could go where there won't be any other horses to stretch out a bit. But with about 100 horses it's not to easy.