484 DISEASES OF CATTLE. 



immunization, instead of a loss of 90 per cent among breeding stock 

 taken South more than 90 per cent can be saved. The animals should 

 be carefully nursed through the attack and their symptoms treated 

 as indicated on page 487. 



Immunizing inoculations are now being made by the veterinarians 

 of most of the agricultural experiment stations of the Southern States 

 without cost for the services rendered, a charge being made merely 

 for the actual value of food consumed and attendants' wages. These 

 veterinarians have also issued station bulletins which describe fully 

 the necessary steps to be taken in securing the blood and injecting it 

 into the animals to be immunized, so that the stock owner can follow 

 the instructions with prospects of getting good results. 



This operation is not a difficult one, and excellent results will follow 

 where absolute cleanliness and ordinary care have been used, but 

 undoubtedly the best results will be obtained by those who have 

 thoroughly familiarized themselves with the nature of the disease 

 and are experienced in extracting blood from animals. Two methods 

 are in use and will be described separately. One consists in drawing 

 the blood from the jugular vein of an immune animal and immedi- 

 ately injecting it into the cattle to be immunized. It is compara- 

 tively simple, requires few instruments, and can be satisfactorily 

 carried out where a small number of animals are to be immunized 

 and if a suitable immune animal is close at hand. First, select an 

 immune animal which is in good health and which is infested with 

 fever ticks or had them the preceding year. Fasten the animal 

 securely, either by tying, throwing, or by placing in a chute. Clip 

 the hair from a space about i inches in diameter over the jugular vein 

 on the upper third of the neck, wash the skin thoroughly with a 5 per 

 cent solution of carbolic acid, and then fasten a strap or rope around 

 the neck below the hairless area and draw it tight in order that the 

 blood in the vein will be stopped, causing distension. With a large 

 hypodermic syringe needle, previously sterilized in a 5 per cent car- 

 bolic-acid solution, puncture the vein at a slight angle, directing the 

 point forward. When the needle enters the vein the point can be 

 rotated freely in contrast to the restricted movements if still in the 

 tissues, and the blood will either drop or flow from the opening in the 

 needle. Attach the disinfected syringe to the needle with piston in 

 and gradually draw out the piston until the chamber of the syringe 

 is full of blood, when the needle is withdrawn. The blood, before it 

 has had time to clot, is immediately injected into the animals to be 

 immunized and which have been previously tied or restrained, the 

 hair clipped, and the skin disinfected at the seat of injection in the 

 region of the shoulder. Inject then from 1 to 3 c. c, according to 

 the age of the animal, under the skin of each animal until the blood 

 is exhausted. When more animals are to be inoculated than one 

 syringeful will inject, the operation may be repeated in the same 

 manner. The only objection to this method is the possibility of the 



