62 TECHNIC OF ANIMAL INOCULATION 



6. After the injection has been given, either with a syringe or, when 

 the inoculum is large in amount by gravity from a large jar, the needle 

 is quickly withdrawn. Bleeding ceases as soon as pressure over the 

 vein is removed. 



Sheep and Goats. In sheep and goats the intravenous injection is 

 given into the external jugular vein, directly through the skin. The 

 hair is clipped, and the part shaved and disinfected. Compression by 

 the finger at the root of the neck renders the vein more prominent. In- 

 jections are also readily given through a popliteal or a femoral vein. 

 If necessary, a small incision may be made through the skin in order to 

 expose the vein chosen for the injection. 



Dog. Dogs may be injected through the external Jugular or pop- 

 liteal veins. The animal should be fastened to the operating-table. 



2. There is a small vein just beneath the skin, in the median line, 

 along the anterior surface of the leg, which is readily accessible. Clip 

 away the hair, and disinfect with iodin and alcohol. Direct the as- 

 sistant to grasp the thigh just above the knee, to distend the vein and 

 prevent movement, and make a small incision directly in the median 

 line. A small vein is seen at once. Dissect free or pick up gently with 

 fine forceps and insert a small sharp needle. The injection can thus 

 be readily given. Withdraw the needle, apply firm pressure, and insert 

 a single stitch. Bind the wound with a few turns of a gauze bandage 

 or seal with collodion and cotton. 



METHOD OF MAKING INTRACARDIAL INOCULATION 



1. Guinea-pigs may be injected by the intracardial route instead of 

 intravenously. The technic is not, as a rule, more difficult, and no ill 

 effects are noticed. Not infrequently, however, attempts to inject in 

 the heart fail, and frequent trials are not permissible on account of 

 the danger of injuring the organ. 



2. The animal is tied to the operating board, or held firmly by an 

 assistant; an anesthetic may be given. 



3. Determine the point of maximum pulsation to the left of the 

 sternum by palpation, and quickly insert a thin, sharp needle at the 

 selected area. A flow of blood indicates that the needle has entered the 

 heart. Attach the previously filled syringe and slowly inj ect the contents. 



4. Detach the syringe in order to make sure that the injection was 

 intracardial, as intended, which is indicated by a flow of blood; then 

 quickly withdraw the needle. The puncture wound may be sealed with 

 collodion. 



