TETANUS TRISMUS LOCKED-JAW. 467 



muscles, both voluntary and involuntary, constituting the 

 disease known as locked-jaw or tetanus. 



There as two distinct forms of the disorder, differing in 

 origin ; the one succeeds the infliction of wounds and other 

 injuries, and is termed traumatic ; whereas the other is of 

 primary origin or idiopathic. Traumatic tetanus follows 

 surgical operations or accidental wounds which are often 

 very slight. The spasms may supervene shortly after the 

 occurrence of any injury, the time not exceeding fifteen or 

 twenty minutes, though usually they are not observed until 

 the wounds are nearly or quite healed. Predisposing causes 

 such as constitutional tendency, cold weather, low condi- 

 tion, starvation, aid in the development of traumatic 

 tetanus, though it is impossible to induce the disease at 

 will by subjecting animals to influences which are at times 

 sufficient to bring about an attack. Traumatic tetanus 

 supervenes often after docking when the tail is cauterised, 

 or after wounds of the feet or joints. It not unfrequently 

 occurs in severe forms of cynanche or strangles after opening 

 of the abscesses, or when suppuration does not occur freely. 

 A cause of traumatic tetanus is the deposition of dirt in a 

 wound, such as a particle of rust or a portion of steel from 

 the breaking of an instrument. Punctured wounds are 

 more likely to be followed by tetanus than incised ones, 

 and we therefore have the disease after subcutaneous divi- 

 sion of tendons or muscles, as in nicking. Traumatic 

 tetanus not unfrequently follows after the occurrence of 

 severe comminuted fractures. 



Idiopathic tetanus is due to causes the nature of which 

 is not always obvious. Cold is capable of inducing it, and 

 to this cause I attribute cases such as I have seen of 

 tetanus supervening suddenly when horses are clipped 

 during very cold weather. It is seen in old, worn-out 



