PRINCIPLES OF VETERINARY SURGERY 183 



lungs, the pleura, the peritoneum, etc., but the shock from 

 these causes is less severe than that occurring from en- 

 gorgement of the abdominal viscera. The post-mortem in 

 these cases always confirms the exactness of the theory; the 

 splanchnic circulatory apparatus is found over-full of stag- 

 nated blood. 



3. Painful and Bloody Operations. — The shock that fol- 

 lows long, painful, sanguineous surgical operations on ani- 

 mals is similar to that following the accidental wound. 

 Loss of blood, associated with the pain and the injury of a 

 surgical operation, augments the degree of shock. But sur- 

 gical shock may occur mysteriously in the absence of both 

 pain and haemorrhage. In man it often follows the blood- 

 less operation performed under the influence of profound 

 anaesthesia, and in these instances it is not unusual for the 

 symptoms to make their appearance before the patient has 

 revived from the anaesthetic. In animals this particular 

 phase of shock is seldom, if ever, observed. The collapse 

 of an animal occurring during the procedure of an operation 

 is generally traceable to some internal rupture or chloroform 

 syncope. It is after the long operation, the painful opera- 

 tion, and the sanguinary operation, but especially a com- 

 bination of all three, that shock is so frequently observed in 

 veterinary surgical operations. Some minutes, and some- 

 times several hours elapse before the grave symptoms ap- 

 pear. The patient is already in the standing posture and 

 returned to the stall before any unusual symptoms are ob- 

 served. Sometimes after a long operation performed under 

 the restraint of casting ropes, the shock may prevent the 

 patient from arising immediately. Some assistance may be 

 necessary to return the patient to the standing attitude. 



The influence of pain in the production of surgical shock 

 in animals is shown by the fact that it seldom follows an 

 operation performed under anaesthesia, and especially from 



