386 DISEASES OF CATTLE. 



lung affected, the extent of the lesions, the degree and kind of patho 

 logical changes in the interlobular tissue, the color of the lung on cross 

 section and the amount of hepatization. In individual cases, therefore, 

 it is often necessary in the present condition of science to take into 

 account the history of the animal, the course of the disease, and the 

 eommuuicability of the affection before a diagnosis can be made between 

 the two diseases. 



Prevention and treatment. The prevention of pleuro-pneumouia, as of 

 other contagious diseases, consists in keeping animals so that they will 

 not be exposed to the contagion. As the disease only arises by conta- 

 gion; there is no possibility of an animal becoming affected with it 

 unless it has been exposed. If, therefore, pleuro-pneuniouia exists in 

 a locality the owner of healthy cattle should make every effort to keep 

 his animals from coming near those which are affected, or near any 

 which have been exposed. He should be equally particular not to allow 

 any person who has been on the infected premises to visit his own pas- 

 tures, stables, or cattle. 



If pleuro-pneumonia breaks out in a herd every animal in that herd 

 should be slaughtered, the stables should be thoroughly cleaned and 

 disinfected, and no other cattle should be allowed on the premises until 

 a period of ninety days has elapsed. 



Medical treatment of affected animals is unavailing and should not 

 be attempted. Xo matter how valuable the diseased animals may have 

 been before they contracted the disease, they should be at once destroyed 

 and the contagion eradicated. This is the best policy for the individ- 

 ual as well as for the community. 



The eradication of this disease by local or national governments can 

 only be successful when the same principles are adopted and carried 

 out as are here recommended for individual stables. It is then a diffi- 

 cult undertaking, simply because the contagion is generally widely dis- 

 seminated before any measures are adopted, and because a great major- 

 ity of cattle-owners will never report the existence of the disease. Reg- 

 ulations must therefore be enforced which will insure the prompt dis- 

 covery of every herd in which the disease appears, as well as the 

 destruction of all diseased and exposed animals and the thorough disin- 

 fection of the premises. 



To discover pleuro-pneumonia sufficiently early for this purpose the 

 district supposed to be infected should be clearly defined and a suffi- 

 cient force of inspectors should be constantly employed to inspect every 

 herd in that district at least once in two weeks, or better, once a week. 

 Ko bovine animal should be allowed to go out of the defined district 

 alive, and all which enter it should be carefully inspected to insure 

 their freedom from disease. As an assistance to the discovery of dis- 

 eased herds, every animal which dies in the infected district from any 

 cause, and every animal which is slaughtered, even if apparently in 

 good health, should be the subject of a careful post-mortem examination. 

 Many affected herds will be found in this way. 



