Thank You everybody. She was a nice little mare and died way too young. I had planned on keeping her colt for at least a year and will definitely be hanging on to him now.
We do have oleander all over the neighborhood here, it is everywhere in Arizona. However the horses have been stalled for the last week due to flood irrigation and letting things dry out before going out again. I have never seen any signs of oleander in the barn.
About a month ago Angel had a couple of seizures, don't know the cause. Due to her age and health the vet feels that the chances are very high that it was either a heart attack or aneurysm that got her.
I am still in shock. Its hard to explain the feeling of walking in the barn and knowing one of your horses is dead. If she had been old or sick it still would have been a shock but this is something else.
I am going to be clipping her colt in the next few days (hopefully today) and I will post pictures so all his family (that would be you guys) can see how he is doing.
Something to remember: While waiting for them to come pick her up I realised that Angel had not been DNA'd yet. I ran out and pulled mane hairs so I wouldn't have trouble registering her colt. I know its hard to think of things like that and I can't tell you how surprised I am that I thought of it. With having to PQ your babies now get those hair samples out so you aren't kicking yourself later.
Thank you again,
Robin