36 PRINCIPLES OF VETEEINAET SUEGEEY 



What wounds are favorable to tetanus infection f 



Wounds inflicted in dirty parts of the body, as tail, hoof, 

 scrotum, vagina, umhilicus, etc.; punctured wounds, espe- 

 cially nail pricks, coronary caulks, amputation and myotomy 

 of the tail, setoning, castration. 



What animals are subject to tetanus f 



Mainly the horse ; next, lambs and pigs ; then, rarely, 

 •cattle and goats. The dog seems to be almost immune. 



Which are favorite places of the tetanus bacillus ? 



Eich garden earth, land manured with horse manure, 

 street dust. 

 Wliat do inoculation experiments show 9 



The most common form of infection is through earth, 

 while, of course, foreign objects, as nails, splinters, dirty 

 instruments, etc., may convey the bacillus. It does not enter'; 

 the blood current, but localizes in the wound and produces a 

 strychnine-like toxin (Tetanotoxalbumin), which on being 

 absorbed acts upon the central nervous system, giving rise to 

 •certain symptoms. 



X^ive the essential post-mortem changes of tetanus. 



Evident pathological changes are usually absent. i 



How long is the period of incubation ? 



Three to twenty days. 

 Give the symytoms of tetanus ? 



These vary somewhat with the intensity of the intoxica- 

 tion. There is a tonic spasm, especially of the extensors of 

 the hind extremities, neck and masticatory muscles. Ears 

 «rect and stiff, eye partly covered by the nictitans, tail 

 elevated and stiff ; saliva flows from the mouth ; lips some- 



