FAULTY CONFORMATION 149 



complete covering to the sole and frog, and to the bearing 

 surface of the wall. When cold it hardens, without losing 

 the shape given to it, into a hard, leather-like substance. 



Treated in this way, the animal with pumiced feet may 

 yet be capable of earning his living at light labour or upon 

 a farm. 



E. 'EIXGED' OR 'RIBBED' HOOE. 



Definition. — A condition of the hoof in which the wall is 

 marked by a series of well-defined ridges in the horn, each 

 ridge running parallel with the coronary margin. They 



Fig. 82. — Hoof showing the Rings in the Horn brought about 

 by Physiological Causes. 



are known commonly as ' grass rings,' and may be easily 

 distinguished from the more grave condition we have 

 alluded to as following laminitis, by the mere fact that 

 they do not, as do the laminitic rings, approximate each 

 ether in the region of the toe, but that they run round the 

 foot, as we have already said, parallel with each other. 



Causes — This condition is purely a physiological, and 

 not a pathological one, and the words of its more common 

 name, ' grass rings,' sufficiently indicate one of the most 

 common causes. Anything tending to an alternate increase 

 and decrease in the secretion of horn from the coronet will 



