138 BOVINE PATHOLOGY. 



wliicli have recovered from an attack are exempt from the 

 disorder in future. When an animal has been slaughtered 

 after recovery from pleuro-pneumonia, his lungs will be 

 found to exhibit traces of the diseased action. Old ad- 

 hesions to the walls of the thorax^ consolidation, atrophy 

 of certain parts ; while often, it will be found that the 

 portion of the lung which formed the main seat of 

 disease has been thrown off as a slough, and encapsuled 

 by lymph ; or it may have become calcified. An im- 

 portant question for the verification of our diagnosis here 

 presents itself. How are we to distinguish the lungs in 

 this disease from those presenting the conditions observed 

 in sporadic inflammation of the lungs and pleura ? Many 

 skilful veterinary pathologists state that in some cases of 

 sporadic disease the marbled state of the lung occurs, and 

 that hence we are not in a position, from simple inspection 

 of a portion of lung, to determine the nature of the case. 

 Generally the sporadic disorder affects both lungs, and the 

 stage of the disease is uniform throughout, we cannot 

 note the abrupt transitions found in the infectious disease ; 

 also the lymphatic glands are not so much involved. The 

 history of the case will assist us in our inquiry. During 

 life sporadic cases differ from specific in that they are 

 more acute, cannot be traced to contagion, and may 

 generally be put down to some other cause of a non- 

 specific nature. Also abortion takes place ; the grunt is 

 present (see Walley, " Four Bovine Scourges,^^ for a full 

 list of distinguishing features). 



Cases of pleuro-pneumonia are liable to be confused in 

 diagnosis with those of pleural scrofulous deposits known 

 as " grapes.''^ Professor Williams considers that these 

 deposits are very frequently due to changes of pleuritic 

 adhesions, and says that cough during swallowing is 

 diagnostic of their presence, for they tend to compress 

 the oesophagus. His views are not generally accepted. In 

 some cases the differential diagnosis of these two conditions 

 is very unsatisfactory. The history of the case will help 

 us, and we must carefully look for any scrofulous lesions. 



Treatment. — Sometimes, during an enzootic of this 



