Alfalfa Hay for Horses: Myths vs. Reality

Does it really matter if hay has some mold in it? Hay that is high in dust or mold can irritate the horse’s respiratory tract. Optimum athletic performance depends on a healthy respiratory tract, therefore dusty/moldy hay should never be fed to horses used (or intended for) athletic events. A chronic respiratory disease commonly called “heaves” can be aggravated by moldy and dusty hay. Horses with heaves can have so much difficulty breathing that even mild exercise is impossible. In addition, moldy hay may contain toxins that could affect the horse if they are ingested. Horse owners should not rely on the nutritional wisdom of horses to prevent problems associated with moldy hay. Horses will usually avoid small patches of moldy hay, but selectivity decreases as hunger increases. Also, in one study horses accepted slightly moldy red clover just as readily as clean alfalfa