178 HORSESHOEING. 



sinking of the coronet at tlie toe. This produces a change of 

 form of the hoof. The quarters become higher. Rings form 

 upon the wall, and their course is quite characteristic of the 

 disease. At the toe these rings are quite close to one anotlier, 

 but as they pass back toAvards the quarters they gradually 

 separate from one another and recede from the coronary band 

 (Figs. 193, 19i, and 195). 



The wall at the toe is sunken just under the coronet; its 

 lower part, on the contrary, is thrust forward. Later, the white 



Fig. 193. 



Vertical longitudinal section of a foot altered by chronic laminitis: o, hollow wall at toe 

 thrust forward; h, leafy layer much thickened and crumbling ("seedy-toe"); c, dotted line 

 showing limit to which the toe may be rasped away in shoeing; d, dropped sole; e, atrophy 

 of lower sharp edge of os pedis; g, dotted line indicating the height of the perioplic band; h, 

 foot axis. 



line becomes pathologically ividened. The horn of the white 

 line is dry, crumbling, and easily broken down, so that a break 

 in continuity (crack) is apt to occur between the wall and sole, 

 and lead to the formation of a hollow wall ("seedy toe"). 

 Where the inflammation is moderate and is not repeated, healing 

 usually takes place and the horn grows down regularly and in 

 normal direction from the coronet. However, a rather brittle 

 condition of the horn remains permanently. If, on the con- 

 trary, the inflammation was very severe or repeated several 

 times, the homy sole becomes flat just in front of the point of 

 the frog as a result of the sinking of the os pedis, or it may even 



