CASTRATION OP THE DOG 107 



when available, a morpliin and atropin combination 

 given subcutaneously about an hour before operating, 

 is a good practice. The amount of morphin given 

 varies somewhat with different operators, but from 

 one-half to one grain of morphin with 1-100 grain 

 atropin may be given animals weighing about LT) 

 pounds, or larger doses may be used with safety where 

 no other anesthetic is used. The administration of 

 moi'phin an hour before the operation, usually causes 

 sufficient nausea and retching to empty the stomach, — 

 a very desirable effect in a subject that has not been 

 prepared for the operation. Where a trained assistant 

 is obtainable, anesthesia is completed by the adminis- 

 tration of either A. C. E. or chloroform. 



Care should be taken during' the administration of 

 the anesthetic, as a sudden change in position of the 

 subject from the horizontal to the vertical with the 

 abrupt throwing of the weight of the intestines upon 

 the diaphragm, is likely to cause arrest of respiration. 

 Where no operating table is in use, the position of the 

 body should be shifted gradually, and where animals 

 are simply hung by the hind legs, the change of position 

 must be accomplished with care. 



Preparation of the Surgical Field. — For a linea alba 

 incision, a liberal area in the prepubic region is lathered 

 and the hair shaved from a space from two to four 

 inches wide, extending as far forward as the xiphoid 

 cartilage. The soap is then removed with a mild anti- 

 septic solution and the skin dried and painted with tinc- 

 ture of iodin. Towels may be folded in such manner 

 as to cover all the unshaved area, and these iiuiy l)e 

 suspended by means of intestinal clamps oi' other foi'- 

 ceps having limber jaws, by clamping the towels upon 

 the skin over the region of the tensor fascia lata. 



