A SPRAIN OR STRAIN. 



215 



as freely as it should be, and the horse goes on his toe to a cer- 

 tain extent. 



Treatment. — A long rest, a loose box, and the firing iron. A 

 few days aftef the firing, the red iodide of mercury, one part to 

 four or five parts of lard, should be applied. This should be 

 washed oft' in three or four days, and another application made, 

 if necessary. The method of firing will be dealt with more fully 

 at the end of this chapter. 



THOROTJGH-PIN. 



Thorough-pin is a bursal enlargement situated on the side of 

 the hock. It is a distension of the bursa in connection with the 

 flexor pedis perforanus muscle. It varies in size, in some cases 

 no larger than the end of the finger; in other cases it attains the 

 size of the closed hand. Pressure on one 

 side of the limb causes it to disappear on 

 that side and appear on the other. 

 Thorough-pin is generally associated 

 with bog S2:)avin. It rarely produces 

 lameness, and should not be considered 

 as a serious condition. 



The treatment of thorough-pin is 

 about the same as that for wind-galls, 

 bog spavins, and other bursal enlarge- 

 ments. 



CAPPED HOCK. 



Capped hock is the term applied to an 

 enlargement on the point of the hock, 

 and is sometimes due to distension of the 

 small bursa .situated immediately be- 

 neath the skin. In some cases it is a Fig. 57-Capped Hock, 

 distension of the large bursa situated between the gastrocnemii 

 externus and internus. Capped hock is caused by blows, kicks, 

 etc. It may arise from a mere dropsical condition or slug- 



