Both vets agreed - hair analysis is excellent and accurate, best taken from the mane or tail, somewhere where it grows continually, and they can give you the history of any deficiency or toxicity as well. It is best to have a vet do the collection both to make sure they get the root ball, and so, say Princess Pony will hate the vet instead of you, who has to deal with her on a daily basis (think of how annoying it is if someone yanks a piece of hair from your head!) but this is often the best way to tell with horses, especially if there are not other gross symptoms. It depends what part of the country you are in what they need to test for, of course. Does that help? I'll email you the audio files when I get them, but wanted to tell you that part, in any case!
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