336 DEFORMITIES AND DISEASES OF THE HOOF. 



2. IJPEiGHT Hoof. 



The description ' upright ' may be applied to any hoof, the 

 toe of which, when viewed from the side, forms an angle of more 

 than 60° with the ground, and the heels, compared with the toe, 

 appear too high. The relative lengths of heel and toe vary. 

 While in slight cases of upright hoof the length of the toe is 

 scarcely double that of the heel, measured at the posterior 

 border, in aggravated cases the height of the toe and heel may 

 be equal. The toe is then at right angles to the earth, and 

 the quarters nearly perpendicular. The sole is usually very 

 concave, though the os pedis does not always correspond. In 

 walking, the toe is most worn, and (except in the conformation 

 shown by fig. 169) the entire weight of the body falls on the 

 anterior half of the hoof. 



Upright hoof is seen in all classes of horses, and affects both 

 the fore and hind feet. 



The condition is peculiar to the positions shown in figs. 151 

 and 169. It is due to hereditary tendency, or is produced 

 by neglect of the feet in young animals, the toe being dis- 

 proportionately shortened in comparison with the heels, and 

 is apt to follow diseases of the limb, which, for lengthened 

 periods, prevent extension of the fetlock joint. Among such 

 are inflammation of the flexor tendons and of the posterior 

 ligaments of the limb, spavin, and ring bone. Thrush is very 

 apt to accompany this formation of hoof. According to 

 Siedamgrotzky, it is always present in old standing cases of 

 contracted tendon. In consequence of the gradual shortening 

 of the flexor tendons, the os pedis undergoes a partial 

 rotation on its transverse axis. The resulting pressure on the 

 toe leads to the papillae of the coronary band assuming a 

 more upright position, and to the formation of an upright, thin, 

 but firm toe wall. This is followed by a similar change in 

 the heeJs, while, under continued pressure, the anterior portion 

 of the sole becomes flattened and the white line increased in 

 breadth. 



The prognosis depends on whether the condition is congenital, 

 i.e., whether it results from the conformation of the limbs or 

 whether it is acquired. 



