Abstract: A boot for horses' hooves made of flexible material having a sole part and an integral upper part with inner slots at the back, between the sole part and the upper part, provided to accommodate the protruding rear parts of a horseshoe on the hoof. An elastic check tooth is formed at the rear center portion of the upper part. The engagement of the rear parts or "calks" of the horseshoes, together with the tapered shape of the upper, holds the boot on the hoof. The boot preferably extends just high enough to cover the hoof without covering the fleshy parts of the foot.