COMMON DISEASES OF SWINE 333 



(2) "In this method there is injected at the same time with 

 the serum, but in a different place, a small amount of viru- 

 lent blood, or blood taken from a hog very sick with cholera." 

 This method is known as the simultaneous method^ and 

 renders a hog immune for life. It is counted a satisfactory 

 method to use in a herd before it has become infected, but 

 great care must be exercised not to use too much of the 

 virulent blood, lest the hog be given a severe form of the 

 disease. 



(3) " This method is known as the combinatio7i method. 

 The hog is first vaccinated with the serum alone, and ten days 

 later vaccinated with the simultaneous method." This method 

 was originated by the author of the bulletin. Dr. Schoenleber, 

 and the claim is made by him that this is the safest and most 

 satisfactory method that can be employed in an exposed 

 herd. 



The bulletin referred to above gives full directions for 

 vaccinating and handling the herd, but recommends that none 

 but skilled veterinarians perform the operation. 



From very extensive tests which he has made. Dr. Schoen- 

 leber draws the following conclusions: ''Vaccination should 

 be done while the animals are still healthy, but if cholera 

 is present, a large per cent is saved through the use of the 

 serum, and the earlier it is used in an outbreak the greater the 

 per cent saved." 



SWINE PLAGUE. 



Swine plague is sometimes mistaken for hog cholera, and 

 often accompanies the latter disease. It is an infectious disease 

 caused by a germ, and the symptoms are similar to those of 

 cholera. As a rule, the lungs and pleural membrane are in- 



