CHAPTER XVIII 



ON SHOEING AND CARE OF .THE FEET 



826. THE STRUCTURE OF THE FOOT. The horse's 

 foot consists of the hoof and its contents. These 

 contents are the coffin or pedal bone, the navi- 

 cular bone, the small pastern bone and the lower 

 end of the large pastern bone, the ligaments of 

 the joints, the synovial membrane and synovia, 

 the lower ends of the perforans and perforatus 

 tendons, blood-vessels, nerves, lateral cartilages, 

 sensitive laminae, sensitive sole, plantar cushion, 

 coronary substance, and the perioplic ring. 



Thus the hoof is the horny box enclosing the 

 soft structure and the bones. It consists of wall, 

 bars, frog and sole. (P. 138, 139.) The wall is 

 divided into toe, quarters and heel. The bars 

 are formed by the walls turning in at the heels ; 

 these bars do not meet by about in. at the front 

 of the frog. 



827. Wall. The outside of the wall is 

 covered with an epithelial skin (periople) which 

 grows downwards from the perioplic ring. 

 This is Nature's protection to the hoof ; it pre- 

 vents the hoof from drying up and becoming 

 brittle. Hence the common fault of farriers 

 rasping the outside of the hoof is absolutely 

 wrong, and should never be allowed, even at 

 the toes. The hoof grows downwards from the 

 coronary band, and takes eleven to thirteen 

 months at the toe and six months at the heel to 

 grow from top to bottom. The hoof does not 

 grow from the sensitive wall. The wall is 

 thickest at the toe, where the wear is greatest, 

 and thinnest at the heel, to allow of greater 

 elasticity. The thick toe is also necessary, as it 

 is used in propulsion, the toe being the last part 

 of the foot to leave the ground. The elasticity 

 of the heel is also increased by the presence of 

 more moisture in the horn. 



The wall is composed of minute fibres that 

 extend downwards and forwards (hence a 

 quarter crack, or toe crack, extends downwards 

 and forwards). Each fibre starts at the coronary 

 band, and, if this band is cut or destroyed, the 

 hoof will not grow down again below this part. 

 Nature, however, produces a kind of horny 

 substance as a substitute. In quittor operations 

 (Sec. 436) the greatest care must therefore be 

 taken not to damage the coronary band. The 

 outer part of the wall is drier and harder than 

 the inner, due to exposure to air. This is neces- 



sary to resist wear, hence this part should never 

 be rasped. 



If the hoof is partly removed, Nature sends 

 out a secretion temporarily to protect the sensi- 

 tive structure until the hoof has grown down 

 again. A nail cannot, of course, be driven into 

 this temporary structure. As the inner wall of 

 the foot is more vertical and bears more weight, 

 there is greater thickness of hoof at this part 

 than on the outside of the foot. 



The sensitive laminae are attached to the walls 

 of the pedal bone, and are very freely supplied 

 with blood and nerves. Hence great pain results 

 from foot injuries, and blood poisoning is more 

 liable to occur in the horse's foot than in any 

 other part of his body, except his lower jaw. 

 The function of these sensitive laminae is to join 

 the pedal bone to the hoof, and thus they bear 

 most of the weight on the leg ; they also nourish 

 the horny hoof. The growth of the hoof is in- 

 creased by applying stimulants (as cantharides 

 blister) to the coronary band, or coronet, just 

 above the hoof. 



828. Sole. The horny sole is similar in 

 structure to the wall, but grows downwards 

 from the sensitive sole, which is attached to the 

 pedal bone. It is slightly arched. The horny 

 sole takes six months to grow. In health it 

 should be firm, and not spongy. The sole must 

 never be pared away ; only jagged pieces should 

 be removed by the farrier. Under the weight of 

 the body the sole becomes slightly flatter. 



829. The Bars. These divide the sole from 

 the frog. Between them and the frog, on each 

 side of the frog, is a groove or commissure, that 

 leaves room for the expansion of the frog when 

 it is placed on the ground. The bars grow down 

 from the sensitive sole. They must never be 

 pared away ; they should be kept lower than 

 the sole. Contracted heels are very rare with 

 good bars. Their function is to support the wall 

 at the heels and to prevent contracted heels. 

 They increase the bearing surface of the wall 

 and allow for expansion of the heels at each 

 step. 



830. The Frog. This is a wedge-shaped 

 portion of hoof situated between the bars. It 

 grows downwards and forwards from the sensi- 

 tive frog. It takes two months to grow down. 



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