CONTAGIOUS DISEASES OF DOMESTICATED ANIMALS. 7 



left lung was affected with chrouic bronchitis, and many of the bronchi 

 were filled with a thick, white, tenacious pus. 



The disease was brought to this stable in the latter part of December, 

 1882, by a cow dealer who lives near the navy-yard. She presented 

 symptoms of disease in about two weeks after purchase and lingered 

 for six weeks with symptoms of acute lung disease. Three weeks after 

 the death of this first cow a second became sick, with similar symptoms, 

 and died after four weeks' illness. 



Two others were successively affected in a similar manner and died ; 

 and, finally, the fifth came down with the disease about the 1st of May, 

 1883. 



On May 29, 1883, we received at the Veterinary Experiment Station a 

 €0W from the stable of Catharine Bresuahan, of Lincoln avenue. This 

 animal was somewhat tympanitic and stood with arched back, elbows 

 turned out, and extended head. With each expiration there was a loud 

 moan. Examination over the lungs revealed dullness, tenderness, and 

 loss of respiration on the right side. 



This animal died during the night of June 3, and was examined the 

 following day. The right lung was found to be firmly attached to the 

 ribs and diaphragm over nearly the whole surface of contact. This lung 

 was almost completely hepatized; the posterior part was gangrenous; 

 the median portion showed old hepatization, in which there was little 

 difference in color between the lobular and the interlobular tissue, 

 while the anterior portion was freshly hepatized and presented the dis- 

 tinctly marbled appearance seen in acute pleuro-pueumonia, and thought 

 by some to be characteristic of tliat disease. The condition of this lung 

 showed bej'ond questionthattheintlammation was a progressive one, and, 

 beginning in the posterior portion of the organ, had successively in- 

 vaded the median and anterior portions. 



The existence of intiammation of different ages, showing the i)ro- 

 gressive character of the disease, is now regarded by the leading author- 

 ities of Europe as the most satisfactory means of distinguishing between 

 contagious pleuropneumonia and the sporadic intlammations of the res- 

 piratory organs. The pleural cavity contained about a quart of effusion, 

 and the mucous membrane of the bronchial tubes was of a deep red 

 color. 



This animal presented, consequently, all the s^nnptoms and post-mortem 

 appearances described as peculiar to pleuropneumonia. The only his- 

 tory that could be obtained was that a number of cows had previously 

 been affected in this stable with similar sym])toms. 



September 18, 1883, I examined a cow on Nineteenth street, which had 

 rapid and difficult breathing, with extended head and elbows turned out 

 as in cases of pleuro-pneuinonia. There was dullness over the lower half 

 of both lungs, with resonam',e above, but no res[)iratory murmur could 

 be detected over the left side from the shoulder backward. This ani- 

 mal died on the morning of September 21, and on examination the left 



