Dr Peter Gillespie BVSc MACVS
- The term foot and hoof are often used synonymously. By definition the hoof is the integument of the foot and the foot is the part of the distal limb encased by the hoof.
- The size of the foot is relative to the size of the horse.
- The foot continues to grow in size until a horse is 6 years old.
- The length of the toe is relative to the weight of the horse.
- The pastern and dorsal hoof wall should be parallel – the foot pastern angle should be straight.
- The front feet are more circular in shape to allow for expansion during weight bearing.
- The hind feet are more pointed to allow for traction during propulsion.
- The front feet are never steeper than the hind feet on the same horse.
- The angle of the heel should be within 5 degrees of the angle of the toe.
- The coronary band should form an angle of about 30 degrees with the ground.
- The diameter of the coronary band should be approximately equal to the vertical height of the hoof at the toe.
- When viewed from the solar surface the foot should be as wide as it is long. The sole should be concave.
- A flat sole will impede expansion of the hoof during weight bearing and is more prone to bruising.
- The soles of the front feet should be slightly less concave than those of the hind feet.
- The width of the frog should be 2/3rds of its length – any less and the foot is considered to be contracted.
- The bars should protrude slightly above the level of the sole. They should be about 1cm shorter than the wall to allow for hoof expansion during weight bearing.
- The hoof wall grows on average 1cm a month and should wear about the same amount.
- The part of the foot that bears the most weight will grow the least.
- The foot has several functions:
Conduction of moisture
- The weight on the foot increases three fold when a horse is galloping.
- The hoof is flexible enough to absorb 70-80% of the impact during weight bearing.
- The foot has a landing side and a loading side – the landing side flares out while the loading side becomes more perpendicular in response to weight bearing.
- The outside wall of the hind feet is more slanted than the inside wall to aid in propulsion.
- The centre of gravity of the foot is 1cm back from the point of the frog. In an ideally conformed horse it should be plumb with the centre of gravity of the limb which is at the shoulder.
- Hoof quality is directly related to its moisture content which varies for different parts. The hoof wall is approximately 25% water, the sole 33% and the frog 50%.
- Extremely dry walls (<20% moisture) or extremely wet walls (>30%) are weaker and more susceptible to failure from loading forces.
- Water is nature’s hoof conditioner. It is the only preparation that has been shown to consistently have a positive effect on maintaining hoof moisture balance.
- As water is constantly being lost from the hoof it is important to replace it on a daily basis. Generally daily immersion in water for 10-15 minutes is sufficient.
- Oil and fat based hoof dressings cannot moisturise the hoof wall.
- The weight of the shoe should be as light as possible – 15 grams at the foot transfers to 450 grams at the shoulder.
- The foot is the dominant site of lameness in the performance horse. It should always be eliminated as a cause of lameness.