62 DISEASES OF THE LUNGS 



tissue forming a sequester which protects the rest of the 

 organism. Such cases will heal. 



Treatment. — The treatment is unsatisfactory. Intra- 

 tracheal injections of antiseptics are of no value except 

 in the early stages. The treatment suggested for catarrhal 

 pneumonia is usually followed. 



Metastatic Pneumonia. — Definition. — A secondary pneu- 

 monia the result of embolism. 



Etiology. — ^Metastatic pneumonia is the result of a spread 

 of infection via embolism from a primary focus containing 

 pus bacteria, septic bacteria or necrosis bacilli which reach 

 the lung through the blood. The primary focus is usually 

 an abscess occurring in the course of strangles, purulent 

 arthritis, gangrenous pododermatitis, phlegmon of the 

 hind limbs, etc. It may also result from navel infection 

 (thrombophlebitis), of which it is a common sequel, or it 

 may originate from inflammation of the jugular or saphenous 

 veins. It is a frequent sequel of acute gastro-intestinal 

 disorders in calves. 



Necropsy. — Metastatic or embolic pneumonia is charac- 

 terized by multiple abscess or necrotic centers which occur 

 throughout the lung tissue. At the same time there are 

 symptoms of septicemia and pyemia. 



Symptoms. — ^The symptoms of metastatic pneumonia are 

 often quite vague as the embolic center cannot always 

 be determined by percussion and auscultation. Where a 

 primary abscess exists, and the patient suddenly shows 

 septic fever, dyspnea and cough a metastatic pneumonia 

 should be thought of. In the later stages sjrmptom? of 

 abscess of the lung (pm-ulent nasal discharge, etc.) are 

 significant. 



Treatment. — Treatment is unavailing. 



Interstitial Pneumonia (Chronic Pneumonia). — Definition. 

 — Interstitial pneumonia is an inflammation of the connective 

 tissue of the lung which proliferates causing induration or 

 sclerosis. 



Etiology. — It is a secondary disease and may follow any form 

 of pneumonia especially the catarrhal. It most frequently 

 occurs in the course of chronic pulmonary tuberculosis, 



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