206 LAMENESS OF THE HORSE 



.scapular muscles. It is especially important to provide for the 

 subject to be exercised when there is atrophy of the quadriceps 

 muscles following azoturia. 



In addition to the foregoing, good results have attended the 

 use of intramuscular injections of oxygon. The technie of the 

 operation consists in preparing the area of skin which covers 

 the atrophied muscles as for any operation. The hair is clipped 

 over five or six or more circular areas of about an inch in diame- 

 ter; the skin is cleansed and then painted with tincture of iodin. 



A long heavy sterile needle, which is connected with an oxygen 

 tank by means of six feet of rubber tubing, is thrust into the 

 depths of the affected muscles and the gas is gently introduced 

 into the tissues. One needs exercise extreme care that the gas 

 enter slowly because great pain is produced by the sudden in- 

 jection of the oxygen. Likewise too nmch of the gas must not 

 be introduced at one place. When the oxygen is slowly intro- 

 duced it may be allowed to enter the tissues until the subject 

 gives evidence of experiencing considerable pain, or if the parts 

 are not particularly sensitive, a reasonable amount (enough to 

 cause a mild degree of diffuse inflammation) is introduced at 

 each one of five or six points. In large animals more points 

 of injection may be used. 



No infection or other bad results will follow the execution of 

 a good technie and the treatment may be repeated every three 

 or four weeks until either marked regeneration of tissue is evi- 

 dent or the case is obviously proved hopeless. 



Paralysis of the Obturator Nerve. 



Anatomy. — The obturator nerve, situated at first under tlie 

 peritoneum, accompanies the ol)turator artery through the ob- 

 turator foramen and gaining tlie muscles on the internal face 

 of the thigh, terminates in the obturator externus, adductors, 

 peetineus and gracilis, also giving twigs to the obturator in- 

 ternus (Strange ways). 



Etiology and Occurrence. — This condition occurs upon rare 

 occasions as tlie result of injury such as falls which cause ex- 

 treme abduction of the legs, or in pelvic fracture where the 



