Biological Therapy 



171 



the characteristic symptoms of the disease appear. The 

 period of incubation following such infection is from one to 

 two weeks. 



SYMPTOMS. The first symptom to be observed varies 

 somewhat, depending upon the portion of the body involved. 

 In some instances stiffness constitutes the first symptom 

 while in others it may be an elevation of the tail, a rigidity 

 of the ears, of difficulty in swallowing. As the disease pro- 

 gresses the head and neck become extended and the tail 

 markedly elevated. The ears stand erect, the eyes are 

 sunken with a marked protrusion of the nictitans membrane. 

 The pupils are dilated, the nostril distended and trumpet 

 shaped. The mouth is tightly compressed, and although 

 drooling may be marked it is impossible to open the mouth 

 to any degree. The gait is stilted, the legs barely bend, and 

 the patient will move only when forced to do so. The 

 muscles become tense, almost boardlike to the touch, which 

 interferes with correct respiratory and circulatory activities 

 and intensifies the animal's suffering or may hasten death. 

 The reflex irritability is so materially increased that the 

 animal is extremely sensitive to light, while any unusual 

 noise intensifies the muscular spasms and causes profuse 

 perspiration. The mortality is extremely high, death occur- 

 ring in from two to ten days although consciousness is 

 retained to the end. 



TREATMENT. The patient should be kept in quarters 

 which are quiet and dark. Liquid foods are frequently nec- 

 essary on account of the inability to swallow. Tetanus 

 antitoxin is indicated unless the nervous symptoms are ex- 

 tremely marked. It should be considered that tetanus toxin 

 has a selective action for the nervous system and is en- 

 meshed in the nerve tissue and also that the body is harbor- 

 ing considerable amounts of toxin when symptoms become 

 apparent. Under these circumstances therapeutic results 

 can hardly be expected unless large amounts of antitoxin are 

 used. For this reason injections should consist of from 

 5,000 to 20,000 units, which should be administered intrav- 

 enously and repeated each twelve to twenty-four hours. 



PREVENTION. The effectiveness of tetanus antitoxin 

 in preventing tetanus has been so conclusively demonstrated 

 that this is usually the only precaution which is taken after 

 an injury is received. Many surgeons use a prophylactic 

 injection after all operations. An imunizing injection con- 



