VACCINE-THERAPY 79 



carry through. The syringe is now charged with the neces- 

 sary dose of vaccine ; it is usual to apply a twitch in the 

 horse, although some of them do not resent, especially if 

 the needle is a small one. A fold of skin is then taken up 

 between the left-hand finger and thumb, and the needle 

 firmly plunged through the skin. It is advisable, although 

 not so essential as it is in the human subject, to see all the 

 air is expelled from the fluid-free end of the syringe. 



At the seat of injection there may or may not be a little 

 swelling, and in the case of the dog stiffness, but if there is 

 it usually passes off in a day or two. 



