SANDCRACK, LOOSE WALL, AND SEEDY TOE. 373 



It is commoner in fore than in hind feet, and at the inner 

 than at the outer side. Taken as a whole it is not of in- 

 frequent occurrence, though it only attracts notice when it 

 extends to the soft parts and makes the horse lame. On 

 account of this fact an artificial division between superficial 

 and deep-seated loose wall has been made. The latter causes 

 lameness by reason of the separation extending towards the 

 lower margin of the sensitive wall and there producing super- 

 ficial intlammation or even pus formation. 



Loose wall can only be detected with certainty by removing 

 the shoe and searching the foot, although its presence may 

 sometimes be guessed by the bulging of the lower margin of 

 the wall (fig. 353, a). 



The prognosis depends on whether the separation is super- 

 ficial or deep, and whether it involves a large portion of the 

 wall. Separations occasioning lameness are, like sandcracks, 

 apt to be very troublesome. 



.. (X. 



Fig. 353. — Vertical section of a hoof (semi-diagrammatic), a, loose waU ; b, seedy wall 



(the process has extended furthei'). 



The causes of loose wall are various. When the wall 

 forms an oblique angle with the ground, it is more liable to 

 separate than when upright. Wide, fiat hoofs, therefore, are 

 its commonest seat, but laterally distorted and contracted hoofs 

 also exhibit the condition. The soft horn composing the white 

 line is doubtless largely responsible for the occurrence of 

 separations, offering, as it does, little resistance to the 

 ammoniacal fluids, etc., to which it is so often exposed, and 

 suffering more severely than contiguous parts from the heat of 

 the shoe when applied for fitting. Contact with manure alters 

 its nature, the heat of the shoe dries it, and causes cracks and 

 irregular strains in different portions, while the downward 

 progress of the wall, which rather favours tension and cracking 

 of the sole even when sound, contributes to the production of 



