Page 1161 - Adams and Stashak's Lameness in Horses, 7th Edition

Foot Care and Farriery 1127

be detached from the underlying tissue. Lameness is Fissure in Central Sulci of the Frog
49
present in severe cases that involve the dermis, and swell­ There will often be a fissure located in the central
VetBooks.ir sulcus of the frog in horses that have thrush. The author
ing of the distal limb may be seen.
feels the fissure is a primary structural defect in the soft
tissue structures in the palmar/plantar section of the
foot that secondarily becomes infected leading to thrush.
The fissure is often seen in horses with a hoof capsule
distortion (such as low heels with instability and sheared
heels), a recessed frog, compromised soft tissue structures,
and an abnormal strike pattern. The asymmetrical landing
pattern results in an unequal force placed on each heel,
causing the heels to move in opposite directions. This
movement in opposite directions causes a fissure to form
in the weakest part of the soft tissue, which is the central
sulcus of the frog (Figure 11.49A and B). Significant
movement in the fissure can often be demonstrated by
moving the heel bulb in opposite directions.

Treatment
Farriery
Treatment for thrush begins with improving the hoof
capsule, the conformation of the palmar/foot, and the
health of the frog. Thrush will not be resolved as long as
the frog remains recessed below the ground surface of
the foot. The amount of improvement in the frog is
correlated with the amount of chronic damage espe­
cially involving the frog dermis. If the horse can be given
time off work, the shoes should be removed, the heels
trimmed to the same plane as the frog, the perimeter of
the hoof wall rounded, and the horse left barefoot.
When barefoot, load is shared by all the structures of
Figure 11.48. An untrimmed foot with thrush, the frog recessed the palmar foot, and the integrity of structures improves
24
below the ground surface of the foot, sheared heel conformation, and rapidly and it appears to promote regrowth. Treatment
a fissure present in the central sulci of the frog extending to the hairline. of the thrush as described below is performed daily.

A B
Figure 11.49. (A) Foot conformation showing the frog receded A and B) results in the formation of a fissure in the base of the frog
and asymmetric foot landing leading to sheared heels. The difference (yellow arrows; A and B) (B) A horse with severe club foot combined
in force on each heel exerted in the opposite directions (red arrows; with a sheared heel. Note the loss of frog mass between the heels.