LAMENESS IN THE FORE LEG 181 



tremity in a state of volar flexion. In cases where extensive 

 injury has been inflicted, and great pain exists, the foot is kept 

 off the ground niiieh of the time and it may be swung back and 

 forth as in all painful affections of the extremity. 



Nail punctures cause typical supporting-leg-lameness and in 

 some cases certain peculiarities of locomotory impediment are 

 worthy of notice. Punctures of the region of the heel, which 

 directly affect or involve the deep tendon sheath, cause a type 

 of lameness wherein pain is augmented, when dorsal flexion of 

 the extremity occurs as well as when weight is borne. Wounds 

 in the region of the toe of the hind feet sometimes cause the 

 subject to carry the extremity considerably in advance of the 

 point where it is planted and, just before placing the foot on the 

 ground, it is carried backward a little way — ten or twelve inches. 



However, diagnosis of nail puncture is l)ased on the finding of 

 the characteristic wound or resultant local changes. 



Course and Prognosis. — The nature of the progress and the 

 manner of termination of these cases are variable. If the coffin 

 joint has been invaded, and a septic arthritis exists, the condi- 

 tion is at once grave. An open and infected tendon sheath, 

 while not so serious, constitutes a condition which is distressing, 

 and recovery is slow even under the most favorable conditions. 

 Where a heavy, rigid and sharp nail enters the foot, in such 

 manner that fracture of the third phalanx (os pedis) occurs, 

 this complication makes for a protraction of the condition. Ex- 

 perience teaches that tlie natural course and termination in 

 these cases are modified by the location and depth of the injury, 

 virulency of the contagium and resistance of the subject to such 

 infection. 



Prevention. — In all horses w^liich are kept at such work that 

 exposure to nail punctures is frequent, a practical means of pre- 

 vention of such injuries consists in ^e employment of heavy 

 sole leather or suitable sheet metal to cover the sole of the foot 

 and, at the same time, confine oakum and tar in contact with 

 the solar surface to prevent the introduction of foreign material 

 between the foot and such protecting appliances. Further, if 

 drivers and owners could be impressed with the serious complica- 

 tions which so frequently attend wounds of this kind, undoubt- 



