PRIlSrclpLES- OF VETERINARY SURGERY 465 



fnust be due to a micro-organism other than tlie bacilhis of 

 Nicolaier, perhaps the toxin of the pneumococcus. It is, per- 

 haps, a toxic form of pneumonia. Marcheux has shown that 

 the pneumococcus has a powerful action on the nervous sys- 

 tem. He has found that epidemics of cerebro-spina! men- 

 ingitis have been confounded with epidemics of tetanus. 

 These studies lead to the conclusion that the pneumococcus 

 might be taken into account in the epidemics of tetanus fol- 

 lowing great battles. 



Symptoms in the Horse. — In the horse a variable period' 

 of incubation elapses between the introduction of the tetanic 

 germs and the appearance of the first symptoms. The aver- 

 age duration of the period of incubation is two weeks, but it 

 is, however, subject to remarkable variations. Certain ex- 

 ceptional events have shown that tetanus may appear a few 

 hours after the accident. Hoffman observed it six hours 

 after the prick of a nail. It usually develops between the 

 twelfth to the thirtieth day. 



ANNOTATION. 



The supposed short periods of incubation so frequently mentioned in 

 connection with tetanus probably never occur. Tetanic contractions fol- 

 lowing shortly after the infliction of a wound are no doubt due in every 

 case, to some previous trauma that has escaped notice, or that cannot be 

 found at the time of the appearance of the disease. In all of these cases the 

 second trauma is a mere coincidence. Numerous incidents of this kind have 

 been observed. A large draft horse sustained a frightful injury to the fet- 

 lock by wedging a heel calk into the slot of a cable car track. In falling to 

 the ground while making desperate efforts to release the fixed limb, the fetlock 

 was dislocated. The subject was carted to the stable with an ambulance, be- 

 mg unable to support weight on the injured leg. The pain was extreme. Six 

 hours later an examination revealed the subject afflicted with acute tetanus, 

 which the owner, of course, attributed to the dislocated joint. A careful ex- 

 amination of the feet, however, disclosed a forgotten nail puncture that had 

 been sustained some ten days earlier. Another interesting case followed 

 two tail operations,' — ^pricking and docking, — ^performed by two different veter- 

 inarians. On a certain date one of the veterinarians performed caudal my- 

 otomy on a valuable coach horse. Ten days later a second surgeon ampu- 

 tated the tail. Three days after the second operation the patient fell sick 

 with sub-acute tetanus, and died two weeks later. The intensity of the dis- 

 ease pointed to the myotomy as the cause, while the relative rarity of tetanus 

 from caudal myotomy as compared with amputation, was pointed out as an 



