212 



MODERN HORSE MANAGEMENT 



[chap. 



Its function is to bear weight, to prevent slip- 

 ping, to prevent shocks by acting as a cushion, 

 and to expand the heels whenever the foot is 

 brought to the ground ; therefore it should 

 always be on the ground (except in navicular 

 disease). On its under surface is a groove called 

 the cleft, which runs along the median line of 

 the foot ; this groove should be shallow and 

 rounded. Its purpose is to increase the mobility 

 of the frog and to decrease the liability of slip- 

 ping. At its base (back) are two bulbs, called 

 the bulbs of the heel. 



The frog is much softer and more like a 

 cushion than the hoof walls and sole. It con- 

 tains water and some oil, and its fibres are 

 wavy, causing it to be more elastic. If a horse 

 stands on a dry floor for long, the frog becomes 

 too hard. A horse in motion normally brings 

 his heels to the ground first, but in navicular 

 disease he may bring the toe down first. The 

 frog must never be cut, only jagged pieces being 

 trimmed off. 



The heels spread every time the frog comes 

 to the ground ; hence high calkins, which keep 

 the frog off the ground, tend to cause contracted 

 heels and diseased feet. The frog should touch 

 the ground every time the foot is brought to the 

 ground. The grooves on each side of the frog 

 allow for its expansion. 



831. The sensitive frog is situated imme- 

 diately above the frog and below the plantar 

 cushion ; it is situated between the retrossal 

 processes of the pedal bone, and is similar in 

 shape to the under-surface of the frog ; the frog 

 grows from it. 



The plantar cushion, or frog-pad, is situated 

 between the lateral cartilages and above the 

 sensitive frog, and is composed of a network of 

 fibrous bands, having the interstices filled with 

 elastic tissue. The plantar cushion prevents jar 

 or concussion, and also plays an important part 

 in the action of the foot. The frog below it must, 

 therefore, touch the ground. 



832. Lateral Cartilages. — On each side of 

 the pedal bone, i.e. on each wing, or basilar pro- 

 cess, of the pedal bone, is attached a plate of 

 cartilage. These are situated just inside the 

 wall of the hoof. They support the heels and 

 give elasticity, allowing the heels to expand 

 whenever the plantar cushion expands. They 

 are not very vascular, and they therefore very 

 easily become diseased, producing quittor, and 

 they may even become ossified, producing side- 

 bone. {See Sec. 432.) 



They are joined together by inelastic fibres 

 that pass through the plantar cushion, thus pre- 

 venting the heels from spreading too much. 

 The lateral cartilages form an elastic wall to the 

 posterior part of the foot and give attachment to 

 the sensitive laminae. 



As the foot expands, the lateral cartilages 

 prevent any disturbance between the sensitive 



and insensitive laminee. They also, while in 

 motion, assist the circulation in the veins 

 situated within their structure. 



833. Mechanism of the Foot. — 'When the 

 horse's foot is brought down the heel normally 

 touches the ground first, and therefore great 

 concussion is brought upon the heel, which is 

 not transmitted through the limb. This concus- 

 sion is overcome by the elasticity in the fetlock 

 and pastern joints ; the compression and lateral 

 expansion of the sole, and therefore the descent 

 of the pedal bone ; the compression and lateral 

 expansion of the frog, sensitive frog and plantar 

 cushion, and, finally, the expansion of the heels, 

 due to the expansion of the plantar cushion. 



The expansion of the frog widens the bars 

 and the expansion of the plantar cushion widens 

 the lateral cartilages, i.e. increases the width 

 between them. 



Apart from the perfect shock-absorbing and 

 non-slipping mechanism of the frog when it 

 touches the ground, the foot cannot keep healthy 

 and remain uncontracted at the heels unless this 

 expansion takes place freely. Hence the great 

 importance of not allowing any horse to have its 

 frog interfered with, as is so outrageously and 

 commonly the case with many farriers. 



This expansion of the foot allows it to " give," 

 instead of offering resistance as anything solid 

 would. This " give " is sufficient to prevent 

 fracture. A bar shoe in no way affords the 

 required pressure on a horse's frog. The only 

 justifiable occasion when a high-heeled shoe 

 should be used is to relieve pain in navicular 

 disease by relieving frog pressure, and for the 

 purpose of temporarily removing the strain off 

 the back tendons, or suspensory ligaments, after 

 a sprain. 



834. Principles of Shoeing. 



Rasping. — The primary essential of good 

 shoeing in all cases is that the outside of the wall 

 be not rasped. As explained in Sec. 827, if 

 the periople on the outside of the foot is rasped, 

 the hoof becomes hard and brittle. If merely the 

 edge of the toe is taken off, called " dumping," 

 then the bearing surface on the ground is made 

 smaller, and the ends of the fibres are exposed, 

 as Nature requires they should not be. Farriers 

 rasp the foot to save trouble ; they fit the foot to 

 the shoe instead of the shoe to the foot. 



835. Paring. — Great care must be taken to 

 make both the feet of the same length when 

 paring the foot, as is usually done when the 

 horse is re-shod, or at any rate once a month. 

 Every time a foot is re-shod the walls will have 

 grown to a certain extent since the foot was last 

 shod ; this extra growth, but no more, has to be 

 rasped or pared away. This is done by paring 

 the under-surface of the wall only with the 

 farrier's knife, and then making the surface quite 

 level with the rasp. On no account must any 

 part except the under surface of the wall and any 



