Suggest Remedy For Wheezing And Breathing Difficulty

I have a coming 29 year old gelding who has been in good health his whole life (I ve been his only owner). About a month ago he started to have labored breathing. He doesn t make any wheezy noises. Sometimes he has little caughing spells, but they pass & are really not that often. The main thing is, his nostrils are almost always flared & his sides (his barrel) looks like he just got done running. The other day he had a small trickle of blood from one nostril. He has never had breathing problems in his life & has always been fed clean, dust free grass hay. He is stalled at night (barn is well ventilated & stall cleaned daily) & he has a sheltered turn-out, so he is out during the day. I have been unemployed for a long time & cannot afford to call out a vet for my elderly horse. I was very glad to find this site online ... I hope you may be able to suggest something that might ease my horse s breathing problem. Is there anything available for horses that might be effective like enhalers for people with COPD? Like a feed supplement? Thank you very much. Sincerely Debbie & my old guy Skip