Etiology. Symptoms. Treatment 743' 



10. Paralysis of the Sciatic Nerve. 



Etiology. The following causes have been recorded : Kick- 

 ing (Albert), punctured wounds, falling from a height (Hol- 

 ler), falling (Polfiorow), and myelitis due to distemper. Pa- 

 ralysis of the sciatic nerve associated with paralysis of the fore 

 limb of the opposite side has been observed by Friis in the 

 horse and by Moller in the dog. In a case recorded by Labat the 

 l)aralysis was due to rupture of a pelvic abscess, and in one by 

 Cadeac to pressure on the nerv^e by a sarcoma. The disease is 

 observed frequently in dourine owing to neuritis. 



Symptoms. In complete unilateral paralysis of the sciatic 

 nerve there is loss of power in the lower portions of the biceps 

 femoris and the semitendinosus, and of all the muscles below 

 the stifle joint. The animal is unable to flex the stifle joint, nor 

 can it flex or extend the hock or joints of the foot. In the con- 

 dition of rest the leg hangs relaxed, but if placed in the proper 

 position is able to support the body because the stifle joint is 

 fixed by the extensors attached to the patella and consequently 

 the lower joints are fixed. There is always marked flexion of 

 the hock. During movement the foot is dragged along the 

 ground and the weight of the body is borne by the toes in the 

 position of plantar flexion. In consequence of this the skin 

 covering the toes becomes abraded. There may be loss of sen- 

 sation in the portion of the limb below the stifle, but on the other 

 hand there may be hyperesthesia. 



If the paralysis be bilateral the picture presented resem- 

 bles that seen in lumbar paralysis, but differential diagnosis may 

 be based upon the absence of functional disturl)ances of the 

 bladder and rectum, the normal sensilnlity of the inner sur- 

 face of the thigh, the active movements executed by the tail and 

 the hip joint. Atrophy tends to appear early in the paralyzed 

 muscles, as in all cases of peripheral paralysis. 



Treatment. A cure may at most be looked for if the par- 

 alysis be due to an injury. The treatment indicated is that 

 advised by Schimmel for supra-scapular paralvsis (see page 

 739). 



Literature. Cadeac, J. Vet., 1907, 396; Pr. Mil. Vb., 1901, 104. 



Sciatica. In the neighborhood of Saglio in Italy, Giovanoli has 

 frequently observed in goats and cattle, a condition resembling sciat- 

 ica, due to an inflammation of the sciatic nerve. The condition was 

 thought to be due to cold and badly constructed staliles. The stalls 

 which were paved Mith stone were too short and were provided be- 

 hind with open drains that were too deep, -with the result that when 

 the animals were lying down, the hip joints were snlije; ted to great 

 pressure against the sharp edge of the stalls. In spite of the 

 fact that similar stable construction Avas found in other places, 



