SUMMARY OF EVIDENCE ON PLEURO-PNEUMONIA. 291 



are almost unanimous in the opinion that it is not applicable to 

 pi euro-pneumonia. It would require to be extended consider- 

 ably in order to ensure that all animals remaining after exposure 

 to an outbreak were free from the disease. 



According to some a lengthened quarantine would especially 

 be required where inoculation had been practised ; but according 

 to others it would especially be required where inoculation had 

 not been practised. This is one of the points on which inocula- 

 tors and non-inoculators contradict each other. 



11. There is a very general consensus of opinion among 

 veterinary inspectors that if they were allowed, without personal 

 risk, to slaughter an animal suspected, they would frequently be 

 able to nip an outbreak in the bud. Pieuro-pneumonia in its 

 early stage exhibits no pathognomonic symptoms, and therefore 

 veterinary surgeons have to wait until the disease has made 

 some headway before they are sufficiently certain of its nature 

 to justify them in ordering an animal to be slaughtered. 



These are the main facts and opinions elicited by the queries, 

 and taken in conjunction with the evidence given above they 

 afford a fair means of estimating the extent of our knowledge 

 regarding the infectiousness of the disease and the value of the 

 means at present adopted to prevent its spread. 



Now that the Government have taken up the matter, and have 

 consented to appoint a committee of inquiry, it may be well to 

 state shortly what are the points regarding which we are in 

 doubt or in ignorance, but which it is desirable to have investi- 

 gated and cleared up. 



It is the opinion of many that an animal may have what 

 might be called a slight attack of pieuro-pneumonia, which, 

 after running a mild course, passes off without leaving any 

 permanent lesion of the lung ; while others hold that there is 

 no perfect resolution of the hing lesion, but that there always 

 remains some scar or encysted part which may at any time, under 

 favouring circumstances, recrudesce, and be a source of infection. 



If the former view is correct, it points to the possibility of 

 some kind of remedial treatment being discovered which may 

 cut short or modify the progress of the disease. If the latter 

 view is the correct one, it points to the importance of knowing 

 whether an animal has had the disease, or is passing through 

 it in a mild form. 



It is still doubtful if the incubative stage of the disease ever 

 exceeds fifty days, although instances are recorded in which it 

 has seemed to last for five or six months. 



It is not known at what stage of the incubative period the 

 disease becomes infectious, or whether it is at all infectious 

 during that period. 



