The hard structure at the bottom of a horse's leg. The hoof is the remnant, after eons of evolution, of the original toes of Eohippus, the primeval horse. The ergot and chestnut are also such remnants and may likely disappear with further evolution. However, the original toes still exist as bony elements within the horse's hoof.
Although a horse's feet look solid and tough, they are actually full of delicate structures and are protected only partially by the hard outer wall. The sole of the foot is softer than the wall; the frog, a wedge-shaped area of soft tissue beginning at the heel and reaching two-thirds of the way toward the toe, is quite soft.
The shapes of front and hind feet are slightly different, but both grow outer hoof wall that extends beyond the softer portions, keeping them out of contact with most small pebbles on the ground; a large stone, however, may bruise even the artificially raised sole of a shod foot. Keeping a horse's feet in good condition is essential for soundness.
An area of collected pus within a horse's hoof. Abscesses will make the horse lame. They may be caused by a puncture of the sole of the hoof, an infected stone bruise to the sole, or a horseshoe nail that entered (or "quicked") the sensitive tissues within the hoof.
Treatment by the veterinarian involves piercing the sole of the hoof to reach the abscess and allow for drainage. Follow-up nursing care involves soaking the foot in Epsom salts. Often, the veterinarian will also prescribe topical and sometimes even injectable antibiotics.
Bruised Sole or Corn
Because the sole of the foot is not as hard as the load-bearing outer hoof wall, bruises can occur on hard or rocky ground. Letting shoes stay on too long can also cause bruising; the bulb of the heel may press on the metal, causing bruising beneath the sole, as a sharp rock might. A bruise or com on the sole of the feet appears as a reddish discoloration on the sole; lameness might be the first clue, however.
Feet should be large but in proportion to the horse's body. Small feet will suffer extra concussion and increased wear and tear; few horses have feet that are too big, but some horses (and some breeds, such as the Quarter Horse) may have feet that are too small, and can develop unsoundness later in life.
Unshod horses often experience cracks and chips of the lower part of the hoof, but these are rarely serious. A shod horse may also develop cracks, usually starting in the hoof wall at ground level, traveling upward.
A crack may also start in the heel or quarter area and travel horizontally around the food because of weakness of the wall in that area, perhaps as the result of a blow or injury. Minor cracks are generally dealt with as routine matter by the farrier each time he visits. Some cracks, however, call for veterinary care or corrective shoeing by the farrier. Deep cracks may make the horse lame, as may those caused by injury to the coronary band.
FounderOvereating, especially grain
Drinking large amounts of cold water when overheated
Uterine infections in mares that have recently given birth, often caused by retained placenta
grazing on lush pasture; this is more likely to affect ponies than horses, although it may affect either; and various other causes, including viral respiratory infections, some drugs, and the overeating of beet tops
Also called laminitis, founder is inflammation of the sensitive laminae of the foot. It can be caused by the following
Hoof growth is essential for soundness. Growth is enhanced by exercise, proper nutrition, and proper trimming and shoeing. A hoof grows about 1/2 inch per month in weanlings and about 1/3 inch per month in mature horses.
Navicular Disease (Navicular Syndrome)
This common condition is caused by inflammation of the tissues surrounding the small navicular bone in the front foot (or feet), followed by physiologic changes to the navicular bone. It begins as an irritation of the navicular bone and the deep flexor tendon, and causes intermittent lameness of one or both front feet. The condition often goes undetected until it is quite severe.
Predisposing conditions includeHard work, on unforgiving surface
Disproportionately small feet
and upright pasterns.
Most shod horses grow enough new hoof to need trimming every six to eight weeks, and sometimes in as little as five weeks during hot weather or substantially increased work. Horses that are unshod may wear down hoof naturally and need trimming about every 8 weeks.
Shoeing must be done properly for the foot to function normally and for the horse to stay sound. The farrier must take into account the natural shape and size of the horse's foot and leg, the work the horse is doing, and any injuries to the foot or other areas the horse has suffered.
Proper shoeing can protect the hoof wall from excessive wear and damage, increase traction, correct gaits, and reduce discomfort in horses with various physical problems.
The hoof wall is the outer layer of the foot, made of horny material that encases and protects the sensitive structures within the foot. The hoof wall also provides a firm foundation on which to bear the weight of the horse.
See also Farrier; Horse shoes