Hmm, if the vet said everything was fine, then I suggest you find another vet. For a horse to drop weight quickly and lose energy, even completely discounting the nosebleed, then the horse is most definitely not "fine".

So what did the vet say about the weight loss? There is much information missing here.

Hmmm i'd get another vet out, doesnt seem right at all. Can you give us more information about what happened, any other signs you may have seen of the horse maybe being off? nosebleeds dont just happen for no reason. I hope your boy is okay :(

The vet believed the weight loss was due to her teeth being too sharp, so unable to eat correctly and therefore not getting enough nutrients etc from feed. The blood results are also back now, she was a little anemic, but has started to get better herself already, also have put her on a general vitamin supplement to help this along. He didn't seem as concernd about the nosebleed once he found out it was only one nostral after exercise, however checked to make sire she had no blood in the lungs and checked bits of her face too for the same reason although not sure about exactly what bits, said he was checking to make sure it was just air going through not blood. She is actually now pretty much back to her usual energetic self now, and has regained alot of the lost weight, something she had actually started doing when the vet came, so she is feeling much better!
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The signs I noticed of her being off were:
the quick weight loss
the nosebleed from one nostral
and her lack of energy, which I noticed first, as she is certainly not a laidback, calm horse usually and by her being quite lazy, coming in from field at first, then whilst being ridden, I was quite worried, then the weight loss was noticed and then abit later the nosebleed came
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