CHAPTER II. 



INFLAMMATIONS OF THE PODODERM (PODODERMATITIS). 



1. Nailing. 



Wounds of the velvety tissue of the sole or of the podophyl- 

 lous tissue of the wall, caused by nails which have been driven 

 into the hoof for the purpose of fastening the shoe, are usually 

 termed " nailing." 



We distinguish direct and indirect nailing ; the former is noticed 

 immediately, the latter later. 



In direct nailing the nail passes directly into the pododerm 

 (velvety tissue of the sole, podophyllous tissue) ; the wound pro- 

 duced may vary from a simple puncture of the pododerm to 

 chipping of the border of the os pedis, and is always aocompa- 

 nied by bleeding, even though it may not always be noticed. 



In indirect nailing the nail does not pass entirely through the 

 horn capsule, but very close to the sensitive tissues, and crowds 

 the soft horn inward against them. This inward bulging presses 

 upon the pododerm and causes inflammation and lameness, which 

 may not manifest themselves for several days. 



Symptoms. — The first symptom of direct nailing is instant pain, 

 indicated by flinching or a jerking of the limb, showing that the 

 nail has taken a wrong course, and then a more or less profuse 

 hemorrhage. Usually the blood flows from the nail-hole, or the 

 nail when withdrawn may merely show a blood-stain at its point; 

 however, internal bleeding may occur without any external man- 

 ifestations. The symptoms of indirect naihng are entirely dif- 

 ferent. In this case pain does not arise immediately, but later, 

 sometimes as soon as the horse attempts to bear his weight upon 

 the shod foot. In the latter case, on holding up the opposite foot 

 the animal sways backward and throws his weight upon the 

 132 



