PLETTBO-PNETJMONIA., PULMONARY MTJERAIN, &o. 195 



vails at certain seasons of the year, and is most com- 

 mon in the late fail and early spring, or during damp 

 chilly weather. Some animals are more liable to at- 

 tack than others ; it is not so frequent and is more 

 manageable in the open country than in extensive 

 close stables in large towns, where animals are crowd- 

 ed together, live an unnatural life, and are milked 

 very dry in order to increase the daily yield. Many 

 persons suppose it to arise from some atmospheric 

 condition similar to that of cholera, and it is generally 

 considered contagious, that is, communicated from 

 diseased to healthy cows by contact or immediate 

 contiguity. 



SYMPTOMS. These have been found to vary in dif- 

 ferent epidemics and seasons, nor does every animal 

 attacked present all the symptoms of the entire dis- 

 ease. Yet, taking several animals together, the com- 

 plete picture of the disease will be found, and each 

 animal will also present sufficient characteristic symp- 

 toms to identify the malady. In the first stage the 

 attack has been known to vary, thus : the attack com- 

 ing on with great violence, and running a rapid course 

 in spite of all treatment ; or, it may come on slowly 

 and insidiously, the animal not seeming very ill until 

 her lungs are diseased beyond all hope of recovery; 

 or, it may announce itself with violent purging, great 

 weakness, and rapid loss of flesh. 



The majority of cases, however, present the follow- 

 ing symptoms : a short, dry, husky cough which is 

 heard only occasionally, and which is highly charac- 



