Lung Plague in Cattle. 66 1 



In some cases the active morbid processes subside, but are not 

 quite arrested and the malady assumes a chronic form, the exu- 

 dates become organized, causing a sclerotic or morbid condition 

 of the lung and especially of the interlobular tissue, which com- 

 presses and carnifies the lung tissue, or leads to necrotic changes 

 and the formation of sequestra, or again to liquefaction and the 

 formation of vomicae. Here the proliferation of the germ may 

 go on, though little new tissue is invaded, and the animal may 

 remain infecting for a long period. The patient remains thin, 

 and weak, is easily blown under exercise, has a small, accelerated 

 pulse, little power of digestion or assimilation, shows frequent 

 tympanies, and may have profuse diuresis or diarrhoea. The 

 cough is frequent, often paroxysmal, easily roused, loose, 

 mucous, painful and may be attended by muco-purulent dis- 

 charge. Such animals are liable to die in the end in marasmus. 



In some cases the malady is complicated by other infections, 

 leading to the formation of abscesses in the lungs, pleurae, chest 

 walls, bronchial glands, joints or elsewhere, or tuberculous de- 

 posits may complicate the lung plague, and there may be an 

 early death or a long drawn out decline. 



Diagnosis. So many different afEections resemble lung plague 

 closely during life, that a certain means of diagnosis is a great 

 desideratum. Yet many points help one to reach a reasonably 

 certain diagnosis : 



1. Does lung plague exist in the country ? If not, the presump- 

 tion is very strongly against it. 



2. Have the suspected animals been recently imported from a 

 lung plague infected country ? or have they been in contact with 

 animals recently imported from such a country ? 



3. Have they been fed on provender imported from such a 

 country ? 



4. Have they been attended by a man recently from such a 

 •country and whose clothes have not been sterilized ? 



5. Have they been carried on any imperfectly disinfected car or 

 .ship which has carried the cattle of such country ? 



6. Has the affection attacked a considerable proportion of the 

 lierd at the same time ? A rare thing with lung plague. 



7. Has the attack come on slowly and insidiously? Very 

 characteristic of lung plague. 



