It is then drawn back out of these airways into the tube and collected. The sample is analyzed for bacteria, and, more importantly, for cell types that would indicate the beginnings of an allergic response. There is no definitive number of cells that determine early heaves, but the exam can point out a potential problem. Since heaves closely resembles emphysema in humans, human methods of testing in the diagnosis and evaluation of equine heaves patients have been tried. Respirometry, for example, measures the force produced by breathing.
Humans blow into a special device that measures the force of their exhalation.
Horses are nose breathers, so a special device that covers their nostrils is used to record their breathing efforts. Horses that score significantly lower than normal on these tests can be identified, and some early cases of heaves may be diagnosed in this manner, especially when respirometry measurements are combined with the cellular results of bronchio-aveolar lavage. Prevention of heaves amounts to avoiding allergens and environmental toxins that might cause the disease. Researchers have made progress in determining what to avoid and how to better manage horses with problems. The amount of dust around a horse's nose throughout a normal day is three times higher than dust levels allowed in factories, says Michigan State University veterinarian Edwin Robinson.