Improvements in veterinary science and the growing commitment of owners to the care of their horses have led to a significant increase in the longevity of horses. The percentage of horses that are geriatric (20 years or older) keeps rising, and owners continue to seek out information about the special needs of geriatric horses. Attention to hoof care and recognition of common foot problems are an important part of caring for the older horse. The old axiom “no hoof, no horse” certainly rings true for the older horse, too.
Fun Hoof Facts
· The hoof of the fetus is already well formed by the third month of pregnancy (just over a quarter of the gestation).
· The hoof wall grows from the coronary band at the top of the hoof. A multitude of thin projections called papillae generate the hard keratinized material commonly referred to as horn that makes up the hard shell of the hoof.
· The horn of the sole does not grow from the coronary band, but from its own germinative tissue that mirrors the bottom of the coffin bone.
· There are long, thin, shallow, sheet-like reflections of the inner hoof wall that run the full length of the hoof. These reflections are called the lamina, and there are about 600 to 800 of them in each hoof.
· Within each reflection there are 100 or so secondary branches. These laminae interdigitate with mirror reflections of deeper tissues. This provides the support for the coffin bone within the hoof capsule.
· Inflammation of the laminae of the hoof is laminitis.
· The white line represents the deeper, unpigmented horn from the hoof wall, where it attaches to the outer margin of the sole.
Nutrition
You may be asking yourself if this is still an article about hoof problems. Actually, attending to the special nutritional needs of the geriatric horse is an important aspect to preventing many hoof problems. Older horses’ nutritional needs are different than younger adult horses; in fact, they are more like younger growing horses. They need relatively high protein (12% to 14%) and higher fat (7% to 10%). The calcium-to-phosphorus ratio they require is in a narrower range and should be kept close to 1.5:1. They require fiber that is good quality and has high digestibility. Many older horses suffer from dental and respiratory problems that necessitate special feeds (such as equine senior feeds or beet pulp). Biotin is an important B-vitamin component of keratin that improves growth and integrity of the horn.
Supplementation reportedly reduces horn brittleness and cracking. Biotin should be supplemented on the order of 15 to 30 mg per day. Zinc is another particularly important nutrient in the formation of healthy horn and is also found in many hoof supplements.
Laminitis
As mentioned above, laminitis refers to inflammation of the laminae within the hoof. When laminitis is of sufficient severity to result in failure of the normal support laminae provide to the coffin bone, the coffin bone will rotate or sink out of position. This is what is meant by founder (or chronic laminitis). Outward signs of founder include a dished hoof wall (steeper in the upper part of the wall and more sloping in the lower part), diverging fever rings in the horn (closer together in front, and widening further apart as the rings course toward the heels), dropped sole, widening of the white line (“seedy toe”) and contracted heels.
Laminitis is more prevalent among geriatric horses than in younger equines. Poor hoof quality, poor nutrition, neglectful hoof care, and poor environment contribute to this higher incidence. Cushing’s disease is another factor.
Cushing’s disease and Equine Metabolic Syndrome (EMS) have been very common topics in popular equine magazines for years. Suffice it to say here that these tend to be seen with greater frequency as horses get increasingly old. Although not completely understood, horses with Cushing’s or EMS are prone to laminitis.
Early recognition and treatment is important to the long term outcome. Nutrition, pain control, and corrective trimming and shoeing are critical aspects of laminitis care that should be discussed with your farrier and veterinarian.
Regular hoof care is extremely important to promoting healthy, stable, functional feet. Equally important is providing the proper nutrition, a safe facility, a clean environment, and regular exercise. All of these, along with a little regular grooming and a lot of kindness and love, will help your horse reach a healthy, ripe old age.
Check back next month for part 2 in this series, a look at subsolar abscesses, thrush, and hoof wall cracks.
