70 DADD'S VETERINARY MEDICINE AND SURGERY. 
TreTranus, on 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 lics 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 FOR TETANUS OB LOOKED-Jaw. 
BxeuansTION.—On placing a hand 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, as 
seen In the above picture. This ia the diagnostic cymptom 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- 
sounded ; 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 
triamus; but it is only a variety of the same disease, and, therefore. 
