It has been alleged that some races of horses are exempt from this disease. Among these the Arabian, Persian, Barb, Spanish and Portuguese are especially named but their immunity in all probability depends on the feeding and management rather than on any peculiarity of breed. The countries where these horses are met with are not subject to a prolonged winter but yield green food throughout the greater part of the year, and it is a notorious fact that no horse becomes broken winded at pasture. The Arabians moreover “feed their horses on the scanty plants which the borders of the deserts supply and when these are wanting they are fed on a little barley with chopped straw, withered herbs, roots dragged from the sands, dates when these can be obtained, and in cases of need the milk of the camel. They drink at long intervals and in moderate quantities,” (Low). Since an habitually overloaded stomach is the most common cause of _heaves_ the absence of the affection in the Arab is not surprising. But the Arab unfortunately enjoys no such security in England or America. Concerning the Barb, Delwart remarks that after a day’s hard work, fasting, he is fed on six or seven pounds only of barley, and without the cut straw that the Arab is allowed in similar circumstances. In Spain and Portugal horses at work are fed on broken wheat and barley straw, from twelve to twenty-five pounds, and barley from six to twelve pounds daily, according to the size of the animal and the demands upon his strength. The mares are constantly at pasture and according to the rainfall they are starved or in abundance. Green food and a limited straw and grain diet are precisely the conditions in which broken wind does not appear. Rodriguez, veterinarian to the queen says that the disease was unknown to Spain until the cultivation of red clover, lucerne, and sainfoin. At Aranjuez, horses fed on the hay of these plants, lost vigor and wind and several became decidedly broken winded. All were, however, restored to health and vigor by a return to their former diet. Count Cardenas found that his horses gained in flesh on the new fodder, but that symptoms of broken wind developed themselves rapidly. In France, M. Demoussy records similar facts. In Segala, where the aliment is substantially hay, broken winded horses abound, whilst in the adjacent district of Causse where horses are fed through the winter on straw and barley broken by the mules feet in the act of threshing or treading out, the disease is virtually unknown.