MORBID ANATOMY III 



the spinal cord are rare. The lungs remain unchanged, or at 

 most exhibit a post mortem oedema. By microscopical exami- 

 nation, the specific bacteria are found everywhere in the body, 

 especially in the spleen and kidneys, and to a less extent in 

 the blood. 



§ 95. Differential diagnosis. Swine erysipelas is to be 

 differentiated from (i) hog cholera and swine plague. The 

 frequent reddening of the skin in these diseases together with 

 the modified lesions so frequently observed, may cause confu- 

 sion. The bacteriological examination will enable the positive 

 diagnosis to be made. (See hog cholera and swine plague.) 



(2) From anthrax which is very rare in swine. Here, 

 too, the bacteriological examination discloses the true nature 

 of the disease. 



(3) Erythemata due to various dietary causes. 



The significance of a deep reddening of the skin about 

 the head, abdomen and thighs of pigs is not fully determined. 

 It is clear, however, that such a condition often occurs in the 

 absence, so far as present knowledge goes, of a specific infection. 



§96. Preventive inoculation, Pasteur's protective in- 

 oculation is at present the chief prophylactic means employed 

 against epizootic erysipelas. The exact method of preparing 

 the inoculation material has not been published. It is known 

 that Pasteur's vaccine is obtained by passing the bacteria 

 through several generations of rabbits in succession and then 

 cultivating them in nutritive fluid. The animals inoculated after 

 Pasteur's method become, according to him, only slightly ill, 

 and acquire immunity to erysipelas. The method of inocula- 

 tion is as follows : the pigs at the age of nine to sixteen weeks 

 are first injected in the subcutaneous connective tissue with a 

 weak vaccine and in ten or twelve days after with a stronger 

 vaccine. 



The results of the practical application of this method 

 show that it immunizes to a certain extent the inoculated 

 animals. However, the risk of the treatment is said not to be 

 insignificant. It is held that the inoculated pigs infect the 

 healthy and may thus spread the disease. Besides, the adop- 

 tion of this system renders the inoculated animals seriously ill, 



