162 



HORSESHOEING. 



d 



.a 



An imaginary transverse vertical section of a hoof 

 stLowing (a) loose wall and (&) hollow wall. 



4. Hollow Wall. 



A hollow wall is one in which a separation has occurred be- 

 tween the middle layer of the wall and the keraphyllous layer. 



This crack or separation 

 Fig. 138. always extends in the di- 



rection of the layers of 

 the wall (Fig. 138, b). 



ccurrenc e. — Quite 

 rare. 



We should suspect a 

 hollow wall when a part 

 of the wall rounds out 

 prominently beyond the rest, 

 and gives forth a hollow (resonant) sound when struck. The 

 white line presents a crack, yet we should hesitate to form a 

 conclusion as to the extent of the separation from the extent of 

 the crack along the white line, since the latter may be consider- 

 ably smaller. The separation extends higher up the wall than in 

 the case of loose wall, frequently to the coronet. The cavity is 

 usually filled with crumbling, disintegrated horn. 



Hollow wall is not often accompanied by pain. Lameness 

 may arise, however, if the hollow section of wall assists in bear- 

 ing the body- weight, and if the animal does fast work upon paved 

 streets. 



Causes. — Mechanical influences resulting in chronic inflamma- 

 tion of fleshy leaves. 



Treatment. — A cure is possible, but requires considerable time. 

 In shoeing, which should always aim to relieve pressure from the 

 hollow section of wall, we cleanse the cavity and fill it with 

 oakum and tar, crude turpentine, or wax. Where the separation 

 is very extensive we use a bar-shoe. 



The time required for complete cure of hollow and loose 

 walls will depend upon the height of the separation (see growth 

 of the hoof, page 71). 



