Expansion” can refer to several aspects of a hoof. Here it defines the difference in width between the shoe and the hoof as seen when looking down at the hoof with the foot on the ground. Expansion is the amount of shoe that extends past the sides of the hoof at the heels. The shoe should fit flush with the hoof from the toe around to the quarters (the widest part of the foot) and then be wider than the hoof (when the horse is freshly shod) by at least the thickness of a dime.
by Richard Klimesh
© 2010 Richard Klimesh © Copyright Information
Expansion room gives the hoof somewhere to go as it changes shape. With each step a horse takes, the heels of the hoof move outward under the horse’s weight. As the foot is lifted, the heels return to their original position. You can usually see evidence of this repetitive heel movement in the form of grooves or shiny areas at the heel area on the hoof surface of a shoe that’s been removed.
Also, because the hoof is cone-shaped, the base of the hoof gets wider as the hoof grows longer. But the steel shoe nailed to the hoof remains its original width. If the shoe is fit too close, with no expansion room at the heels, or if a properly fit shoe is left on too long between shoeings, the hoof wall usually spreads over the edge of the shoe as it grows. When this happens, the reduced bearing surface area of the hoof at the heel is often crushed under the weight of the horse. Then when the hoof is prepared for his next shoeing, the heels have to be trimmed excessively low to get a solid bearing surface. The best shoeing job in the world is worse than worthless if let go too long; letting the hoof grow over the shoe is a direct route down the slippery slope to a Long Toe/Low Heel configuration.
Like extending the heels of the shoe, leaving generous expansion room carries a certain amount of risk: a horse could step on the exposed shoe and pull it off. Upright hooves need less expansion room and can be shod fairly close, while more sloping, spread-out hooves need to be shod “full” with plenty of expansion. Also, a wide foot can be shod like a flared foot (they are often one and the same), with side clips to contain the hoof and prevent it from spreading over the shoe.
The average shoeing cycle ranges from 5 to 8 weeks. A farrier must determine by experience how much expansion room to leave for each hoof. Just the right amount of expansion will result in the hoof growing to the edge of the shoe but not over it at the end of the shoeing cycle. In fact, this is one of the best ways to determine the length of your horse’s shoeing cycle: when the hoof grows flush with the edge of the shoe, it’s time for a reset, if the hoof has grown past the shoe you’re horse is overdue.
The above tips are general guidelines for assessing your horse’s shoeing. Every hoof must be shod as an individual, taking into consideration the horse’s conformation, movement, habits, management and intended use. If the shoeing on your horse varies significantly from the guidelines in this article, or if you have questions about the way your horse is being shod, discuss them with your farrier. A good shoer will not be offended by straightforward questions and should be able to explain in terms you can understand why he’s shoeing your horse in a particular manner. The owner is ultimately the person responsible for providing the horse with proper hoof care. If your shoer is unwilling or unable to provide satisfactory answers to your questions, that may be reason enough to think about putting your horse’s feet in the hands of another farrier.
Thank you Richard ! This is the last part of the article “Is Your Horse Well Shod?”