How to Recognize and Treat 'Heaves' in Horses

Know and recognize 'heaves' in horses. Basically, it's 'asthma' developed to something in the environment which causes an as allergic reaction that constricts the bronchioles (airways) in the lungs and makes it difficult for the animal to breath, causing it to cough and have limited exercising abilities. When is your horse coughing? Does it happen when it is in the indoor arena? In the stall before feeding? Wherever the horse is when feeding hay? The most common sources of heaves in horses are bedding used in stalls, dirt used in floors of arenas, and dusty/moldy hay. On occassion horses are allergic to certain kinds of grasses, but usually heaves is an allergy to something man-made, or as result of keeping hay around too long or in a dusty area. Keep in mind that some of the symptoms in heaves can also be due to heart disease or respiratory infection. The former may be detected by listening to the heart (which should beat at around 30 beats a minute, or less in a well conditioned horse, and without slushy 'murmers'). The latter are treated with antibiotics.

Take the horse away from what you suspect is the offending agent. See it if makes a difference. After two days, is the horse more able to be worked, or run around without coughing? Listen to the horse's lungs after it is taken for or 'sent out' for a run. Do you hear wheezing? Is the breathing heavy or labored? Is the horse running a temperature (above 103 degrees F) or does it have nasal discharge? You may have a respiratory infection rather than heaves, which has to be treated with antibiotics. In any case, give the horse rest from heavy work particularly after it has had a bout of 'coughing', which causes mechanical injury to the lungs that required time to be repaired.

If heaves persists, consider drug therapy. Prednisone, used in people for asthma, is very effective in horses as long as you start at a 'priming dose' and wean the horse down to every other day therapy at lower doses. Prednisone decreases inflammation, aids in healing, and for MANY still poorly understood reasons, decreases allergic reactions. Drugs called Beta 2 agonists (which are in many human inhalers) open up airways in the lungs. You might also consider adding antibiotics to the medical mix, trimethoprim sulfa (the most effective) or over-the-counter-available Penicillin (less effective) to prevent bacterial infections from setting into the lungs.

Try to identify and get rid of the source of heaves, but also keep in mind that you may have one horse that is sensitive to the allergin (dusty hay, for instance) and twenty that aren't. Heaves, like any other allergy, is a very 'individual' disease. Be sure to not push your horse too hard too fast once you eliminate or have treated heaves.