Bruises of the Hoof in Horses
In the equine context, corns are bruises on the sole of the hoof that appear on the angle that is formed by the wall of the hoof and the bar (the side of the frog of the hoof). Bruises in any other part of the hoof sole, such as at the toe, are only referred to as bruises.
Corns can be very painful and uncomfortable. If left untreated they may develop into abscesses, which may require medical treatment to drain and heal properly.
Poorly fitted horseshoes are the primary cause of corns or when a stone becomes wedged between the shoe and the sole of the hoof. Corns are rare among horses that are used barefooted. General sole bruises, however, can have more causes, such as poor hoof conformation, thin soles, soft soles, or excessive riding on hard, rocky surfaces.
Symptoms and Types
Often with a sole bruise, including corns, there is some appearance of inflammation on the sole of the hoof. This is most easily seen in horses with light colored feet. The horse will react when hoof testers are applied to this affected area of the hoof. The horse will be lame, and the degree of lameness will vary with the degree of severity of the bruise. Sometimes the hoof will be warm to the touch.
When the inner layer of connective tissue and vessels that lie below the epidermis of the hoof are involved, bacteria can enter this sensitive tissue, and an abscess forms.
- Poorly fitted horse shoe (i.e., either due to poor hoof growth or hoof that is too large for shoe)
- Stone lodged between hoof and shoe
For sole bruises in general:
- Poor hoof confirmation, such as flat feet
- Thin soles or soft soles
- Direct injury from stones/rocks on harsh ground
- If the hoof wall has been trimmed too short which causes the sole to have greater contact with the ground
Trimming the surface of the hoof should be all that is needed to visualize corns in a horse. The sole of the foot in the area of the bruise or corn will usually be sensitive, discolored, and inflamed. When a veterinarian or farrier places hoof testers on the affected area, the horse will flinch in pain. The combination of these signs in addition to any lameness the horse demonstrates often leads to a straightforward diagnosis.