130 DISEASES OF THE HORSE. 



muscles of the lower jaw are contracted with immense 

 force. 



As the disease continues more muscles become in- 

 volved, and intense pain appears to be suffered. So 

 violent sometimes are the contractions, that I have 

 heard of muscles being lacerated, and very frequently 

 the teeth are injured by the violence of the spasm. As 

 the spasm reaches the abdominal region, the urine is 

 frequently discharged with sudden jerks. It is, how- 

 ever, as frequently retained, as well as the contents of 

 the rectum. At the last stage of this disease the eyes 

 become fixed in their sockets, and the ears tense and 

 rigid, which symptoms are soon followed by a violent 

 convulsion, which terminates in death. 



In dissections after this disorder, a great extent of 

 inflammation is evident, but this is most probably caused 

 by the violent pressure of the muscles. 



Tetanus is usually caused by wounds of the joints, 

 and more especially of the feet, where the nerves are 

 lacerated, and it frequently follows the injury very 

 rapidly ; but occasionally it does not set in until the 

 injury has been healed and totally forgotten. Expos- 

 ing wounds in the course of nerves to cold air is an 

 exciting cause in many cases. 



All rusty nails and other instruments likely to cause 

 a wound in the foot should always be removed from the 

 stable. 



It has been remarked that wounds from which the 

 suppuration is very scanty, or what are termed dry 

 wounds, are frequent precursors of tetanus. 



