Hoof Nutrition Intelligence is a twice-a-month web segment that is designed to add to the education of footcare professionals when it comes to effectively feeding the hoof. The goal of this web-exclusive feature is to zero in on specific areas of hoof nutrition and avoid broad-based articles that simply look at the overall equine feeding situation.
Below you will find Part 1 of the latest question and answer installment that you can share with your footcare clients.
Q: Will quarter cracks have an impact on equine performance?
By Kentucky Equine Research Staff
A: Horses in all disciplines face hoof-related challenges such as quarter cracks. In an effort to better understand these concerns, researchers in Hong Kong investigated the incidence, clinical presentation and future racing performance of Thoroughbreds with quarter cracks over a 9-year period.
A quarter crack is a full-thickness failure of the hoof capsule between the toe and heel that may extend along the entire height of the hoof from the coronary band to the ground. The separation often results in unsoundness due to hoof wall instability or infection of the deep dermal tissue, though many horses remain free of lameness despite the presence of a quarter crack.
Quarter cracks are thought to arise from innate hoof weakness, improper hoof balance, injury or trauma to the coronary band or an infection of the corium, which is part of the internal vascular network of the hoof.
Poor farriery may contribute to hoof imbalance, which could contribute to crack formation. A common finding among horses with quarter cracks is sheared heels, an unevenness of the heels that causes unequal weight-bearing on the bulbs and creates a shearing force absorbed by the hoof capsule.
During the 9-year study, 4,500 horses in a Hong Kong training center were followed. Some 74 horses had at least one quarter crack and 20 horses had two or more quarter cracks. Almost half of the horses with quarter cracks were lame at the onset of the defect.
An overwhelming number of cracks occurred in the front hooves. There was also a proportional difference in the number of cracks in the left rather than the right front hooves. Most cracks occurred on the inside of the hooves.
The quarter cracks were treated in various ways, although the principle treatments included corrective shoeing with a heart-bar shoe, wire stabilization and the use of epoxy or acrylic materials. Treatment goals centered around correcting the hoof imbalance and eliminating uneven movement.
Among 63 horses for which racing performance following treatment was available, 54 horses had at least one start after treatment. When compared to the control horses, there was no significant difference in the number of career races, career wins or career placings for horses with quarter cracks.
Aside from high-quality forage and fortified concentrates, horses that are likely to have poor-quality hooves should be fed a research-proven hoof supplement. Biotin should be a primary ingredient in the supplement, but other ingredients such as methionine, iodine and zinc will further support hoof health.
Kentucky Equine Research is a nutrition consulting company located in Versailles, Ky.
Click here to read part 1of the Nov. 1, 2020 installment of Hoof Nutrition Intelligence: Is there a connection between diet and white line disease? Click here to read more installments of Hoof Nutrition Intelligence.