Often farriers are asked about the rings on the horse’s foot. They have the potential of giving us twelve months of information about a horse’s health.

Visible rings indicate there has been some disturbance in the metabolism of the horse affecting the keratinization of the hoof. The indentation or ring is formed sometime before it is seen.

Rings that are barely visible but parallel are usually called grass rings. These can be caused by changing the horse’s feed source and composition, changes in activity, minor endocrine gland changes, and seasonal changes affecting environmental temperature or moisture.

Left: Grass rings are barely visible and parallel. They signify minor changes in activity, diet or season; Middle: Founder rings are wide apart at the heel due to laminitis causing limited toe growth; Right: Selenium toxicity causes the hoof to separate and eventually slough.

Deeply indented parallel rings are sometimes called fever or laminitis rings. Horses with mild laminitis attacks that cause a reddening of the white line or bruising of the sole at the toe, and horses that have a high fever for an extended period of time may develop these.

Rings that are wider apart at the heel and close together at the toe are founder rings. This foot conformation is also present in horses with an inherited club foot. The coffin bone has rotated and perhaps even sunk in the hoof capsule. When foundered both front hooves are usually involved. In addition to producing visibly detectable ring(s), the foundering or sinking of the coffin bone within the hoof capsule causes the hoof growth rings to distort. Circulation is reduced at the toe due to pressure on the blood vessels of the coronary band and blood is diverted to the heel – causing it to grow faster.

Sinking can be detected by pushing the thumb from above down against the coronary band. If your thumb slips off easily, the bone has not sunk. If the thumb drops into a depression, the bone has sunk. Horses with this condition are called sinkers and have a very poor chance of complete recovery.

In a few severe cases there will be a separation at the coronary band. A small one could be caused by a tread wound or when an abscess breaks out and drains. This hoof defect is called a cleft. Large ones, even encircling the hoof, can be caused by neglected abscesses or by selenium toxicity. In severe cases, the entire hoof may slough along with mane and tail hair. The feed must be changed and an experienced farrier transfers the weight to the frog while a new hoof wall grows down.

Learn to read the hoof. It can give you a year’s worth of information.