592 PIROPLASMA BOVIS 



passes through it into a sterilized glass, and when sufficient blood 

 has been obtained the needle or cannula is withdrawn, the rope 

 around the neck loosened, and the wound bathed with antiseptic 

 solution. 



"To prevent the blood from clotting, after it has been withdrawn 

 it is immediately stirred slowly with a thin glass rod, which has 

 been disinfected, until as much as possible of the clot has collected 

 on it, and it is then withdrawn. The remaining defibrinating blood, 

 or a part of it, is then drawn up into a clean hypodermic syringe, 

 and the quantity to be injected gauged by a small screw-regulator 

 on the piston. 



"The animal to be inoculated is prepared by clipping the hair 

 from off a portion of the skin about the size of the hand behind 

 or a little above the point of the elbow, on the side of the chest; 

 any part where the skin is loose and thin will answer. This is dis- 

 infected as in the case of the supply animal. The skin is then drawn 

 out between the thumb and forefinger of the left hand and an incision 

 made through it with a narrow, sharp-pointed knife or lancet, to 

 allow of easy introduction of the hypodermic needle, care being taken 

 not to injure the chest wall. If the needle is a strong one it may not 

 be necessary to use the lance. The syringe is now attached to the 

 needle and the required amount of blood injected under the skin. 

 After withdrawal of the needle the part is again lightly bathed 

 with the antiseptic solution. Success depends very largely upon the 

 antiseptic precautions taken in the operation. Consequently, all 

 instruments and utensils, the hands of the operator and the operative 

 area of skin should be thoroughly disinfected. 



"The standard amount of blood used at the Louisiana Station for 

 some time has been 1 cubic centimenter (about 16 drops) for animals 

 of any age. Latterly, however, it has been customary to administer 

 a second dose of 2 cubic centimeters after recovery from the fever 

 period. The object is to increase if possible the degree of immunity 

 before the animal is exposed to ticks. After the second injection 

 of blood the patient is kept under observation for ten days or some- 

 what longer, and the temperature taken to watch the course of the 

 fever, should there be any. 



"We have previously stated that the blood before injection was 

 stirred to remove the clot (defibrinated). This is usually done 

 when a number of animals are to be inoculated, to prevent clotting 

 before the work is completed. In the case of a single animal, how- 

 ever, or even two or three, the blood may be drawn directly from 

 the vein of the supply animal into the hypodermic syringe and injected 

 immediately into the other animal or animals/' 



Although inoculation may be performed at any season of the 

 year, the best time in the Southern climate is during the late fall or 

 early winter months. This prevents a too sudden gross infection 

 with ticks when the animal is turned into pasture, as would naturally 

 be the case during the summer months. 



