144 DISEASES OF THE RESPIRATORY ORGANS 



roundino; it is a thin, delicate layer of yellowish tissue and over that 

 a tough layer of red inflamed fibrous tissue; large abscesses may be 

 formed by the fusion of all the infiltrated pulmonary tissue. 



When gangrene has developed, the inflamed catarrhal centre be- 

 comes dirty greenish-brown in color, or in severe cases, almost black. 

 In the early stages the diseased portion is hard and fibrous, l)ut it 

 soon becomes soft and pulpy and filled with a turbid, foetid, greenish 

 serum. When the disease is slow and chronic, the gangrenous spots are 

 limited in size, but generally when the disease assumes the gangrenous 

 form, it becomes diffuse and the animal dies rapidly from exhaustion. 



We recognize the gangrenous form when the breath becomes pu- 

 trid, for in the dog it is almost impossil^le to get any of the discharge that 

 is coughed up, the animal generally swallowing the mucus. Ausculta- 

 tion of the lungs may detect tympanic or metallic sounds, mucous rales 

 and increased bronchial sounds. When gangrene (necrotic pneumonia) 

 has developed, the animal has a putrid breath and a series of alarming 

 symptoms accompanying it — septic fever, chills, and a high tempera- 

 ture, with weak, irregular pulse. If the sputa were examined, we would 

 probaf)ly find numerous micrococci, bacteria, and portions of broken- 

 down lung-tissue. 



(Edema of the Lungs. — This is apt to follow not only pneumonia, 

 but all debilitating diseases that weaken the left side of the heart, and 

 that organ is unable to force the venous blood through the lungs. There 

 is a regurgitation of the blood, and the alveoli and bronchia become filled 

 by a serous fluid which exudes from the blood vessels. The cedematous 

 lung is distended and much larger than normal; on pressure with the 

 finger the indentation remains some time. On section of the lung, a 

 large quantity of reddish foamy fluid exudes from the tissues and the 

 bronchial tulles. 



When oedema of the lungs follows catarrhal pneumonia it gener- 

 ally begins with great difficulty in respiration, labored or stertorous in 

 character, a short, faint cough, and in rare instances a quantity of thin 

 reddish fluid comes from the nose or mouth. On making a physical 

 examination, percussion gives no results but those found in catarrhal 

 pneumonia. On auscultation, we hear rattling bruits all over the chest, 

 especially in the anterior part, and also in the trachea; the blowing sounds 

 may be very loud in some cases, and can be heard some distance from 

 the animal. Death occurs in a short time. Some time before the ac- 

 tual symptoms of oedema appear, the exhausted condition of the heart 

 is indicated by the pulse being irregular, that is, weaker at inspiration 

 than at expiration. 



Therapeutics. — In treating l()l)ular ])neumonia we follow the same 

 eeneral course as we (,lo in broncliitis. Ihc writer obtained the best 



