HORSESHOEING. 85 



about the thickness of an ordinary flat shoe. If it be weakened 

 by paring, it is deprived of its activity, shrinks, and the hoof 

 becomes narrov\r to a corresponding degree. The frog should, 

 therefore, be trimmed only when it is really too prominent. How- 

 ever, loose and diseased particles of horn maybe trimmed away 

 from the frog when it is affected with thrush. 



The bars should be spared and never shortened except when 

 too long. Their union with the wall at the quarters must in no 

 case be weakened, and never cut through (opening up the heels). 

 They should be left as high as the wall at the quarters, or only 

 a little less, while the branches of the sole should lie about one- 

 twelfth of an inch lower. 



The buttress (angle formed by the union of wall and bar) re- 

 quires special attention. In healthy unshod hoofs the bars run 

 backward and outward in a straight line from the point of the 

 frog. In shod hoofs, however, it happens that the buttresses 

 gradually lengthen, curl inward, and press upon the branches of 

 the frog, causing the latter to shrink. In such cases the indica- 

 tion is to remove these prolongations of horn from the buttresses 

 so as to restore to the bars their normal direction. 



The sharp edge of the plantar border of the wall should be 

 broken away with a rasp until the relative thickness of the 

 wall equals its absolute thickness. However, in healthy hoofs, 

 that is, in those whose walls are straight from the coronet to the 

 ground, the outer surface of the wall should never be rasped. 

 The only exceptions to this rule are those cases in which there 

 is an outward bending of the lower edge of the wall, most fre- 

 quent on the inner side wall and quarter. 



With respect to the inclination of the ground-surface of the 

 hoof to the direction of the fetlock axis, as viewed from in 

 front, the following facts are established : 



In the regular standing position of the limbs (seen from in 

 front) the plantar surface of a hoof is at right angles to the foot 

 axis, and the outer and inner walls are of equal heights. 



In the base-vnde position of the limbs the plantar hoof-surface is 



