I was just given a horse. Cass is a 24 y/o arabian and the first time I saw him was a couple of weeks ago. His was trickling watery blood from his right nostril. I didn't think anything of it at the time but its been two weeks and he's still got a bloody nose. I heard weather can cause it and it has been really crazy (hot dry wet cold) in the past few weeks. I can't seem to find the cause to it. Any ideas? It doesn't seem to be bothering him and he's not acting any different. How worried should I be?:?