DIAGNOSIS, DIFFEKENTIAL DIAGNOSIS, PROGNOSIS 69 



ask ourselves whether the two diseases exist in 

 combination. Laboratory examinations may dem- 

 onstrate the presence of a bipolar organism, but 

 they cannot in the course of a few hours deny the 

 presence of the hog cholera virus, and thus they 

 are often dangerously misleading. Return mail 

 diagnoses of " swine plague" or "hemorrhagic 

 septicemia" are without value because they ignore 

 consideration of hog cholera virus, which in this 

 country is present in most outbreaks of rapidly 

 transmissible swine disease. 



Among the diseases from which hog cholera 

 must be differentiated are uncomplicated swine 

 plague, pneumonias due to a variety of causes, sep- 

 ticemias, tuberculosis, anthrax, so-called "flu," 

 various parasitisms, soap poisoning, brine poison- 

 ing, and sudden deaths from such causes as heat- 

 stroke and lightning-stroke. Eouget and rinder- 

 pest are also to be considered in countries in which 

 they are prevalent. 



The differential diagnosis cannot be made by 

 rule of thumb, nor is it possible to summarize 

 or tabulate the determining features of these va- 

 rious maladies, so that the inexperienced observer 

 can distinguish among them. Armed with defi- 

 nite knowledge of the diseases with which he is 

 dealing the diagnostician usually reaches his con- 

 clusions rapidly and accurately. In the absence 

 of such knowledge, a few rules do not suffice. 



