PNEUMONIA OF THE PIG. 715 



among the specimens forwarded to London, it was considered desirable 

 that the departmental committee should institute a series of experi- 

 ments to decide whether we had in this country a form of pneumonia 

 in the pig which Avas communicable from one pig to another. 



Accordingly a series of bacteriological experiments were conducted 

 by Professor McFadyean with a view to isolate, if possible, a micro- 

 organism which would be capable of inducing pneumonia in healthy 

 pigs. A number of diseased lungs, some of which were taken from 

 pigs affected with swine fever, were examined microscopically by him, 

 and, as was to be expected, several organisms were isolated, but they 

 proved to be morphologically and culturally different from the bacillus 

 of swine fever. Inoculations were carried out with these organisms 

 not only subcutaneously but directly into the lung through the walls 

 of the chest, and feeding experiments were also conducted. The 

 results of these experiments were entirely negative ; a certain amount 

 of local injury was caused to the lungs at the seat where they had 

 been punctured, but in no case was either pneumonia or swine fever 

 induced. 



The experiments have therefore demonstrated that the pneumonia 

 found in the lungs of pigs affected with swine fever is not due to the 

 swine fever bacillus. 



The departmental committee arrived at the conclusion that the 

 pneumonia which is occasionally encountered as an independent 

 disease of the pig or in association with swine fever is not ascribable 

 to contagion, but to the presence of organisms which are generally 

 saprophytic in their mode of life, and which only in particular cir- 

 cumstances (such as lowered vitality and diminished resistance on the 

 part of the pig) are able to multiply in the air passages and lung 

 tissue and thus induce pneumonia ; and it appeared to the departmental 

 committee that in this country pneumonia of the pig is sporadic and 

 not contagious or epizootic. 



CONCLUSIONS. 



There is now no reason whatever to believe that there exists at 

 the present time in Great Britain any disease of a contagious nature 

 affecting pigs other than swine fever. The disease of the heart, 

 " verrucous endocarditis," and the pneumonia which are so frequently 

 met with in pigs cannot be regarded as lesions indicative of an attack 

 of swine fever. 



As regards verrucous endocarditis and pneumonia, it may safely 

 be said that they do not exist in England in a contagious form. 



Considering all the evidence, it may reasonably be concluded that 

 the departmental committee were correct in their views when they 



