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 combination 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, und 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. .\s a rule, the lungs and pleural membrane are in- 
