Tetanus. 299 



lowing a castration. The last is rather unreliable as infection 

 may have taken place long after the operation. He quotes cases 

 in the pig and goat, after castration as eight to fourteen days, 

 and one in the dog almost immediately after a bite on the loins. 

 Following the incubation the marked phenomena are tonic con- 

 tractions of groups of muscles beginning usually with those near 

 to the seat of the infected wound and extending with varying rapid- 

 ity to the locomotor muscles generally (limbs, croup, back, loins, 

 neck, tail, abdomen) and those of mastication (jaw) and the eye. 

 The muscles of respiration are only involved at a late date, causing 

 stertorous breathing and it may be asphyxia. Peristalsis is im- 

 paired so that there is some costiveness and tardiness in digestion. 

 Urination becomes difi&cult and infrequent on account of the 

 difficulty of assuming the normal position for the act, and spasm 

 of the sphincter vesicae and dangerous disten.sion of the bladder 

 may follow. The urine is often albuminous and has a high 

 density and color. Priapism is not infrequent in the male. 



The predominance of the spasm in special groups of muscles 



has been the occasion of giving different names to individual cases. 



Trisrmos or lockjaw is that condition in which the muscles of 



the jaws are violently contracted so that the incisors can only be 



separated slightly or not at all. 



Orthrotonos is that condition in which the muscles in tonic 

 spasms .keep the neck, back and loins rigid, straight and un- 

 bending, in one horizontal line. 



Opisthotonos is when the muscles of the spine are in rigid 

 spasm, so that the back and loins are slightly depressed, the tail 

 elevated and trembling, the neck drawn upward with a concave 

 superior border ("ewed"), the head extended and the nose 

 elevated. 



Emprosthotonos is caused by spasms of the muscles of the ventral 

 aspect of the body, with arching of the back and tucking up of 

 the abdomen. 



Pleurosthotonos is when the trunk is spasmodically bent to one 

 side, right or left. 



Spasms of the muscles of the eyeball, cause sinking and 

 apparent diminution of that organ, with the protrusion of the 

 membrana nictitans over one-third, one-half or even more of its 

 front surface. This is often referred to by owners as " hooks ". 



