70 



DADD'S VETERINARY MEDICINE AND SURGERY. 



Tetanus, or Locked Jaw. 



"We recognize tetanus by the unnatural condition of the muscles 

 of various parts of the body, more particularly those of the face 

 and neck. But the fault lies not in the muscles, but in the nervous 

 system. This disease constitutes one of the most terrible and fatal 

 to which the horse is subject. It is not only frightful to look upon, 

 but is productive of the most distressing agony to the animal. 



THE TEST FOB TETANUS OB LOCKED-JAW. 



■xplanation— On placing ahand under the angle of the jaw, and pushing the head In an upward 

 direction, the nictitating membrane (haw) will be suddenly thrown partly over the pupil, a* 

 seen in the above picture. This is the diagnostic symptom of tetanus. 



There is no difficulty in recognizing this disease. It is charac- 

 terized by involuntary and persistent cramps of the voluntary 

 muscles. The muscles which seem first to be affected are those of 

 the jaws, neck, and throat; and soon all the other muscles are in- 

 volved. One of the principal tests for the discovery of the disease 

 is to place a hand under the jaw and raise the head. Immediately 

 • the haw, or nictitating membrane, shoots over the eyeball. (See 

 cut.) There is no other disease with which tetanus can be con- 

 founded ; therefore, a minute description of the symptoms seems 

 superfluous at this point of our argument. 



When the disease affects the muscles of the jaw only, it is called 

 trismus ; but it is only a variety of the same disease, and, therefore. 



