166 



SCIENTIFIC HOKSESHOEING. 



the wall and wiuo^sand 

 cartilages of the coffin- 

 bone and on its upper 

 face by the lower pas- 

 torn bone, and beneath, 

 where lies the e^reatest 

 [)0ssibility of accident, 

 it is guarded by tbe 

 tlexor perforans, the 

 ]ilantar cushion and 

 Fig. 61. hoof, siiowinc. the exteknal char- horn\' frog. (See Fi^. 



ACTER OF NAVI<l'I,.\K DISEASE. 



A, A, Base or ground line over the center of 

 the quarters. B, B, I'pper edge of the coronet. 

 C, C, Falling in of the hoof opposite the seat 

 of disease. The white line across the houf indi- 

 cates the superfluous growth of the hoof, and 

 the extent to which it should be reduced. 



5. and read the anatomy 

 of the i)arts mentioned.) 

 In this disease the 

 flexor perforans be- 

 comes ulcerated where 



it slides over the under 

 face of the navicular bone (at times involving the sesamoid 

 sheath in the process), and the severe pain experienced is from 

 its play over the rough, diseased portion of that bone. This 

 disease is sometimes inherited, but once contracted, is incurable ; 

 a great deal may be done, however, to ease the animal. Two- 

 thirds of the cases of this malady, I believe, 

 are caused by improperly dressing the foot, 

 cutting the frog away, weakened the bars, 

 and thinning the sole; and then driving Fig. 62. di.seased na- 

 over uneven roads, provoking inflammation ^i^'I'i^ar bone, taken 



. FROM THE HOOF (FlG. 



in the tissues and membranes of the foot, g^^ one-h\lf size. 

 which finally communicates' itself to the a, Diseased portion 

 bones and their attachments with one an- "^^ bone, 

 other. 



The above (Fig. 61) represents the back view of a hoof 

 showing the effects of navicular disease by the shrinkage of the 

 outer wall upon the living parts of the foot, immediately below 



