Two of my horses came up lame yesterday. One had a swollen pastern and fetlock the other just tender footed. I gave the one with the swollen foot some bute and decided to wait until today to see if I needed to take him to the vet. Well, this afternoon I went to check my show horse with the swollen foot and it is worse and he can't even move. I called my regular vet and they can't make it out for around an hour and ask if I can bring him in.... so I called the back up guy. My baby was about to fall into the fence, so my husband had to remove to the t-posts as it is temporary electric tape, thank goodness I had sense enough to buy "toppers" for them. Something in my gut started telling me my horse had been poisoned. This sudden sickness and lameness was so odd. He passed a small stool while standing there and it was covered in mucus. The vet gets here and tries to tell me my horse has foundered. I kept asking him what could have caused that as he is not overweight and not being fed high protein and I don't feed him alot of grain. He tried to tell me a change in feed would do it. I just couldn't believe what he was trying to tell me. Well, as we are trying to load him in the trailer I notice my other horse that was gimpy has a swollen back leg now. So the vet inspects him and starts picking away at his hoof saying there is something in there and he probably has an abscess, but he doesn't want to spend alot of time because he wants to get my other horse into the clinic. So, I asked him to wait because I am now very suspicious that something else is going on. I check my three year old filly and gelding in the other pasture and guess what the filly's legs are all swollen. The vet took all their temps and they are 103.5. Now he thinks it's viral and decides not to take my horse to the clinic as it could infect others. After a couple hours of panic and work, we got our two big horses into make shift corrals as we have been awaiting "the stall guy" to come put stalls in our lean-to we built around Christmas time. So, I have been frantically searching the internet for possible causes as I am now more sure this is not viral. How often do animals all get sick at the same exact time? We bought new grass hay on Sunday.... I found information on a noxious weed that causes all the symptoms my babies have called hoary allysum and I think it is the answer. Has anyone else experienced anything like this? We have to get up early in the morning to finish the temporary shelter for the three year olds to shade them from the sun tomorrow in case they still have a fever. Just wanted to share, I'm all wound up and anxious. Prayers will be gladly accepted.