CHAPTER XIII. 



PERIPHERAL NERVE PARALYSIS. 



Anatomy. — The lumbo-sacval plexus furnishes the nerve 

 supply for the muscles of the hind-leg. The anterior 

 portion of the plexus has two important biauches — the 

 crural and obturator nerves. The former supplies the 

 triceps femoris muscle, pectineus and long adductor of the 

 leg ; the latter provides the adductors of the thigh, gracilis 

 and obturator externus. The important part of the posterior 

 portion of the plexus is the great sciatic nerve and its 

 collateral branches ; of these the small femoro-popliteal 

 nerve is distributed to the flexor metatarsi, anterior and 

 lateral extensor of the phalanges, while the tibial nerve 

 supplies the adductors, gastrocnemii and flexors of the 

 foot, — in fact, all the muscles on the posterior surface of 

 the lower portion of the leg. (Chauveau.) 



1. — Tibial Nerve. 



Inspection. — The animal supports weight with the lame 

 leg ; both hock and phalanges are excessively flexed. The 

 hock cannot be extended, the leg is advanced by raising 

 the foot unusually high, and it is put to the ground in a 

 groping manner. Trotting is impossible. 



Palpation. — The lower portions of the hind leg are 

 wanting in sensibility. The gastrocnemii and perforans are 

 flabby and atrophied, in paralysis of some standing. 



2.— Ischiatic Nerve. 



Inspection. —^\\\\e walking, the leg is trailed over the 

 ground. The animal is unable to advance or elevate the leg, 



