HORSESHOEING. 



87 



Fig. 89. 



3. A decrease in height of the hoof, with a slight sinking 

 of the heels. 



4. A flattening (sinking) of the sole, especially in its 

 branches. 



These changes of form are much more pronounced in the 

 half of the hoof that bears the greater weight. 



A hoof while supporting the body-weight has a different form, 

 and the tissues enclosed 

 within it a different posi- 

 tion, than when not bear- 

 ing weight. Since load- 

 ing and unloading of the 

 foot are continually al- 

 ternating, the relations 

 of internal pressure even 

 in the standing animal 

 are continuously chang- 

 ing, so that, strictly 

 speaking, the hoof is 

 never at rest. 



The changes in form 



+nVA -nlflfi^ in f1if» fnllr^w Transverse vertical section through the middle of a 



taKe place in tne lOllOW- ^.^j^^ ^^^^ ^j^^^ ^^^^ ^^ base-wide form, viewed from 



ino" order: the body- behind. The outer wall having been insufficiently low- 



^^ (• 1 ' (• 1 ^'"®*^ ^^^ caused increased wear of the underlying 



weight falls from above branchof the shoe: a, wear of inner branch (beneath 



, the relatively short wall) ; 6, greater wear of outer 



upon the OS COrOnae, OS branch beneath the relatively long wall; c, the horn 



•n P fl i <? and navipnlflr between the dotted line and the shoe represents the 



p e CI 1 s , ana navicular gy^piug je^gth of this outer waii. 

 bone, and at the moment 



that the foot is placed upon the ground is transmitted through 

 the sensitive laminae and homy laminae to the wall. At the in- 

 stant that the fetlock reaches its lowest point the os pedis bears 

 the greatest weight. Under the body-weight the latter yields, 

 and with the navicular bone sinks downward and backward. At 

 the same time the upper posterior portion of the os coronae (Fig. 

 90, A) passes backward and downward between the lateral car- 

 tilages (a), which project above the upper border of the wall, 



