Chronic Fibrous Pneumonia. Pulmonary Sclerosis. 315 



the exudations in surface parts through adjacent lymph plexuses 

 and favors absorption, so the respiratory movements, in a lung no 

 longer inflamed, favors movement and absorption of exuded pro- 

 ducts. Moderate, regular and gradually increasing exercise to 

 increase the breathing becomes therefore a valuable aid in cases 

 of this kind. If improvement is not shown in one' month of 

 treatment the case is usually hopeless, and if unfit for work or 

 breeding the patient may well be destroyed, to avoid further out- 

 lay in keeping it. 



CATTLE. 



Causes. The bovine races are more subject, than the horse, to 

 fibrous degeneration of the lung, mainly because there is less 

 tendency to suppuration, and also because the excess of connec- 

 tive tissue in the organ makes a very favorable basis for the forma- 

 tion of fibrous tissue. It may succeed almost every form of pul- 

 monary inflammation (fibrinous pneumonia, broncho-pneumonia, 

 inhalation pneumonia, tuberculosis, lung plague) and parasites 

 (strongylus micrurus, S. pulmonaris, echinococcus, cysticercus 

 tenuicoUis, distoma magnum, aspergillus, actinomyces) . 



Lesions. The morbid anatomy is, in the main, as in the horse, 

 and like that varies according to the original cause. In lung 

 plague, or the contagious pneumonia of cattle, a large extent of 

 lung may be involved at one place, or if following a sequestrum 

 it may be confined to narrower limits — a firm, small cicatrix : if 

 from broncho-pneumonia there will be evidence of its having ex- 

 tended in a branching manner with the divisions of the bronchia ; 

 if from pleurisy the fibrous plates will be most marked between 

 the outer lobules, while the bronchia will be largely exempt ; in 

 hydatids there will be the small circumscribed nodules of scle- 

 rosis. If from pleurisy there are usually extensive adhesions, 

 and often implication of the pericardium. In all cases in which 

 advanced and extensive fibroid degeneration exists, the obstruc- 

 tion to the pulmonary circulation has determined more or less 

 dilatation of the right heart, and in many cases insufficiency of 

 the auriculo-ventricular valves. In advanced cases also emphy- 

 sema is a marked feature of the, as yet, pervious portions of the 

 lung. 



Symptoms. Failure to establish an early convalescence after 



