354 VETERINARY BACTERIOLOGY 



The antitoxin is generally injected subcutaneously, but in severe 

 cases intravenous, intraneural, and intraspinal injections are 

 made to insure the contact of antitoxin with the toxin present. 

 Its use is doubtless indicated in all cases. As a prophylactic, it 

 has been found quite certainly to prevent the development of 

 tetanus when injected before the appearance of symptoms. In 

 human medicine it is customary to make injections following severe 

 wounds, into which dust and dirt have gained entrance, such as 

 Fourth-of-July wounds. The same may be said with reference 

 to severe wounds, nail-punctures, and similar traumata in the 

 horse. 



Bacteriological Diagnosis. The organism may frequently be 

 recognized in stained mounts of the pus from the wound. The 

 drumstick shape of the sporulating organism is quite characteristic. 

 Isolation in pure culture and animal inoculation may also be used. 

 The symptoms of tetanus are so distinctive, however, that these 

 methods are rarely called into use. 



Transmission. Tetanus is one of the best examples of a non- 

 contagious, infectious disease. Infection occurs practically in- 

 variably directly through the skin. The almost universal pres- 

 ence of the organism about stables renders infection easy. Nail- 

 punctures are particularly apt to result in tetanus, as they introduce 

 the organism deep into the tissues; superficial healing and exclu- 

 sion of air quickly take place, and conditions are then right for 

 rapid multiplication. It should again be emphasized that it seems 

 very difficult for the tetanus bacillus to gain a foothold and pro- 

 liferate, except in tissues that have been injured. The constant 

 presence of these organisms in the intestines does not produce 

 disease. So-called cryptic infections are not of uncommon oc- 

 currence, particularly in the horse. In these the point at which 

 the organism gains entrance to the body is not known. Usually 

 this comes either from the wound having healed superficially, so 

 as to be indistinguishable, or from the wound having born origin- 

 ally so insignificant as to have escaped notice. Some investiga- 

 tors believe that the organism may occasionally ;am nil ranee to 

 the blood-stream from the intestines, but is unable to produce an 

 infection, except when it lodges in tissue traumatically or otherwise 

 injured, such as a broken bone or a bruise. 



