It’s February. What was in the “cocktail?” Hair follicle tests go from about a week back to several months back. And it doesn’t identify WHEN. When did the horse leave the prior barn?
“Back in November, a close friend of mine traveled several states away to go look at a reining horse 2 weeks after a neutral party preformed a PPE on the mare.”
It’s not uncommon for a horse to internalize stress and not show a change in behavior even though something bothers them. These horses seem fine until their stress level reaches a breaking point, then you have a big reaction. I’d say that a move to a new barn is very very stressful to a horse, and maybe this mare has little things that happen that push her over the limit, and the people around her just don’t see it. They say, “She was fine and then all of a sudden with no warning…” No, there were warning signs, you just did not recognize them.
You change behavior with training. But in this case, we have a positive drug test, although we do not have enough information to make the call as to whether or not drugs are causing the behavior.