384 BOVINE PATHOLOGY. 



of blood disorder,, and it also results from the action 

 of certain poisons. There is a wild look of the eye, 

 excitement and sometimes fury, with violent struggling 

 and discharge of frothy saliva from the mouth. 



Diseases of the Spinal Coed have not been diagnosed 

 with thorough accuracy, though Cruzel gives a long 

 account of myelitis, which, he says, is very rare in the 

 ox. Associated with this important nervous centre are 

 two remarkable conditions which, having been described 

 as distinct diseases, must be rather looked upon much in the 

 same light as coma and delirium, they being symptoms 

 which may be dependent upon any of several pathological 

 states. Thus, Tetanus or Locked Jaw may be caused by 

 electric stimulation of a motor nerve or the spinal cord, or 

 by the introduction of strychnia into the system, or by 

 certain conditions of nerves associated with a wound, or, 

 we believe, as a result of the action of cold and other 

 influences. It is simply an excitation of the spinal cord, 

 causing it to throw so many impressions into the motor 

 nerves so closely following one another that tonic spasm 

 results. It may be diffused or circumscribed. In the 

 latter case simply the source of motor-nerve force to the 

 muscles of the head may be affected then the jaws are 

 fixed and the retractor muscle draws the eyeball back 

 into the orbit and so causes persistent protrusion of 

 cartilage -nictitans. This is known as trismus. Again, we 

 may find only the muscles of one side of the body affected 

 (jpleurosthotonos) J or those above the spine (opisthotonos), 

 or those below (emprosthotonos) . In other cases we find 

 a combination of these conditions. In disease is de- 

 scribed as Traumatic when due to wounds, and Idiopathic 

 when no wound can be found to which it may be attri- 

 buted. It must not be supposed that it is only the 

 motor portion of the cord which is affected, for there are 

 indications that hyperaosthesia is present often to a 

 marked degree, thus, excitation of the patient is apt to 

 give rise to exaggeration of the spasm, and quietude is by 

 far the most important feature of treatment. 



Symptoms. — A gradually increasing difficulty is evi- 



