One of my horses had breathing problems,and an occasional cough. I called the vet after he didn't get better for a couple days; they think he had "Heaves", "horse asthma"; RAD (respiratory Airway Disease)....in other words Allergies... I pinned it down to if there is any mold in roundbale..., bad air quality days (hot, muggy), and something in the fall (when the crab grass grows like crazy). He is turned out 24-7, always has been, gets just grass hay (roundbales), and nothing else (well, salt like). Well Dex, did nothing... he gradually improved after a week or two.... researching alot. Decided to start with cheapest treatment and go forward." Air power " had another nsme, when I first started using it. I found if he started to have trouble breathing this would ease it within 24 hours...not 100%, but alot, maybe 60-85% better and the reaction would be gone in a day. They renamed it, and it still helps, not sure if he is worse or they changed formula, but it worked better last year. I still am using it as it helps him more than the farm visit and DEX did... I may need to increase the dose or frequency...but we had a lot of rain this summer, so mold may just be up. Last year I could just give one dose and he was alot better, this year one dose was not as effective, so I give it over several days. Since I am allergic to mold, we often 'react' the same day or with the hay... the difference is I take desentization shots and he can't. This horse is not being ridden and is about 12 ,(and looking for a home ;0)