Cash has had two minor nosebleeds, both on the left nostril, in the last week. He's never had nosebleeds in his life.
After spending a little time on the 'net doing research, bleeding from the nose is highly unusual in a horse, especially if it happens when they're just standing there. As far as I can tell, the most frequent causes (after bonking themselves in the face, which is unlikely here since it's happened twice) are either a tumor or a fungus in one of the gutteral pouches. Neither option has a very good outcome. The fungus in particular is often only treatable by several days in ICU with a catheter to the pouch and continuous anti-fungal drugs, or surgery, and even then the recovery prognosis is poor. The problem is that the fungus eventually destroys the lining between the pouch and the artery, which is why the nosebleeds happen. In most cases, the horse either bleeds out through the nose, or is put down before that can happen.
I'll be honest, I am completely freaked out. My vet is coming out tomorrow to scope him and take samples to see if he's got the fungus. Maybe it's just the dry air or something completely benign, but I'm really, really worried about how this could go down.
Fortunately, if anything is actually wrong Cash is blissfully unaware. He's happily eating, pooping, and hanging out with the other boys. He looks quite the picture of health, actually.