
Hoof wall defects can develop from one or more contributing factors. To name a few, hoof wall quality can be influenced by genetics, environment, microbes, trimming, and nutrition.
1. Genetics
Breeds such as Thoroughbreds are genetically predisposed to thin hoof walls and soles, which increase vulnerability to trauma and cracking. Midline toe cracks can occur in any breed as a result of a genetically related weak laminar attachment of the hoof wall to the coffin bone.

2. Environment
Horses exercising on hard ground or pavement are predisposed to hoof wall cracking due to the higher shock forces on the hoof walls. Also, hooves that often move from wet to dry environments are particularly susceptible to hoof wall cracking. Lastly, the trauma of stepping on hard or sharp objects will generate cracks – especially cracks that form in the bars.
3. Hoof Eating Microbes
Hoof eating microbes require a nutrient-rich environment that is lacking oxygen to flourish. The several different species of bacteria and fungi that have been isolated from infected hooves all have one thing in common – they thrive on the sulfur-containing collagen of the hoof wall. Nail holes and hoof defects provide organisms with easy entry, while wet environments soften the foot and set the stage for microbial invasions. These anaerobic organisms weaken the hoof wall structure. Leading to crumbling, chipping, and cracking.
4. Proper Farrier Trimming
Quarter cracks that start at the coronary band and extend downward are often associated with excessive loading on one side of the hoof wall. Proper farrier trimming and/or shoeing will balance the stresses on the hoof wall and lessen the shocks leading to cracks and hoof wall separations.

5. Nutrition
Whether from wheat, rice, oats or other grains, bran contains phytates. Phytates block the absorption of calcium predisposing the horse to a calcium deficiency and other mineral imbalances. Calcium is important in providing the “glue” for cellular adhesion in the hoof tissue. Calcium deficiency is often a result of diets high in bran and results in weak, crumbly hoof horn.
Supplementation and Hoof Quality
Excessive dietary sulfur can result from MSM supplementation. Excess sulfur interferes with copper metabolism, leading to weak connective tissue structure and poor hoof quality.
Horses supplemented with excessive selenium develop a lack of structure in the hoof horn. The excess selenium replaces the stronger sulfur bonds, resulting in weak hoof horn. As selenium toxicity progresses, the outer hoof wall becomes brittle, noticeable horizontal rings appear, pain develops at the coronary band, and the outer hoof wall may slough.
Growing Out Hoof Wall Defects
The majority of horses will “grow out” hoof wall defects if:
1) The causative factor is identified and avoided (if possible).
2) The horse receives good nutrition and/or a hoof supplement.
3) The defects are treated with non-caustic topical protectants.

Recommended Hoof Supplement: Farrier’s Formula®
For outstanding hoof nutrition, use Farrier’s Formula®: the #1 recommended hoof supplement by farriers in the USA. Farrier’s Formula® will strengthen the hoof wall to inhibit future cracking and hoof defects, and will also increase the growth rate of the hoof horn to overcome existing cracks.
Recommended Hoof Topical: Farrier’s Finish®
To protect the hooves from “hoof eating microbes” and from wet/dry conditions, use Farrier’s Finish®: a hoof disinfectant and conditioner that unlike other products, does not contain harmful chemicals. Farrier’s Finish® destroys the microbes which cause white line disease, thrush, and crumbling hoof wall. It also supports correct hoof capsule moisture balance in excessively wet or dry conditions.

J. Frank Gravlee, DVM, MS, CNS
Founder of Life Data Labs, Inc.
Developer of Farrier’s Formula®
H. Scott Gravlee, DVM, CNS
Equine Nutrition Consultant







