HOW DOUBLE TREATMENT IS GIVEN 403 



cholera in the vicinity at the time. Pigs are especially easy to 

 develop cholera, and whenever an outbreak of the disease is in the 

 neighborhood the pigs should be treated at once by either the single 

 or double method. 



If the pigs are farrowed by sows which have been given the 

 double treatment, they will usually be found to have a power to 

 resist the disease which will make it unnecessary to give any treat- 

 ment until they are about ready to wean. Then the double treat- 

 ment should be used. 



When to Use Double Treatment. — With a review of the con- 

 ditions under which the single method of treatment is used, it is not 

 hard to form rules for the use of the double or serum-simultaneous 

 method. 



Remember that with the serum-simultaneous method we have 

 the decided advantage that we are producing a protection which is 

 not merely going to last for a few weeks, but are actually training 

 the cells of the body in the way to manufacture these germ-fight- 

 ing bodies which produce the disease, and we, in this manner, set 

 up a serum plant in the body of the animal itself by means of which 

 we have provided a continuous source of protection. 



The cases in which this simultaneous or double method is 

 indicated are those in which the infection of cholera has not already 

 made its appearance; that is, in those herds where cholera is not 

 yet present. For instance, if we go out into a herd and find that 

 the disease is already present, several animals perhaps having al- 

 ready died, and a large number showing a high range of tempera- 

 ture, the double treatment would not be indicated. In this herd 

 the virus of cholera is already present, and there is no need to fur- 

 ther increase the amount of this virus by injecting virus-containing 

 blood. In such hogs with high fever simply administer the serum 

 alone in large dosage, even doubling the dose in those cases which 

 show a temperature of 105° F. or higher. By this method we are 

 able to protect the herd against the attack, and at the same time 

 the action of the germs within the body will result in the develop- 

 ment of the power of producing the germ-fighting bodies in suffi- 

 cient number to result in leaving a permanent protection against an 

 attack of the disease. 



In those animals in this herd which do not show a temperature 



