DISEASES OF THE BRONCHIAL TUBES. 129 



BRONCHITIS AND BEONCHO-PNETTMONIA. 



Bronchitis is an inflammation of the bronchial tubes. When this 

 inflammation extends to the air sacs at the termini of the smallest 

 branches of the bronchial tubes, the disease is broncho-pneumonia. 

 Bronchitis affecting the larger tubes is less serious than when the 

 smaller are involved. The disease may be either acute or chronic. 

 The causes are generally much the same as for other diseases of the 

 respiratory organs, noticed in the beginning of this article. The 

 special causes are these : The inhalation of irritating gases and smoke 

 and fluids or solids gaining access to the parts. Bronchitis is occa- 

 sionally associated with influenza and other specific fevers. It also 

 supervenes on common cold or sore throat. 



Symptoms. — The animal appears dull; the appetite is partially or 

 wholly lost ; the head hangs ; the breathing is quickened ; the cough, 

 at first dry, and having somewhat the character of a " barking 

 cough," is succeeded in a few days by a moist, rattling cough; the 

 mouth is hot ; the visible membranes in the nose are red ; the pulse 

 is frequent, and during the first stage is hard and quick, but as 

 the disease advances becomes smaller and more frequent. There is a 

 discharge from the nostrils that is at first whitish, but later becomes 

 creamy or frothy, and still later it is sometimes tinged with blood, 

 and occasionally it may be of a brownish or rusty color. By auscul- 

 tation, or placing the ear to the sides of the chest, unnatural sounds 

 can now be heard. The air passing through the diseased tubes causes 

 a wheezing sound when the small tubes are affected, and a hoarse, 

 cooing, or snoring sound when the larger tubes are involved. After 

 one or two days the dry stage of the disease is succeeded by a moist 

 state of the membrane. The ear now detects a different sound, 

 caused by the bursting of the bubbles as the air passes through the 

 fluid, which is the exudate of inflammation and the augmented mu- 

 cous secretions of the membrane. The mucus may be secreted in 

 great abundance, which, by blocking up the tubes, may cause a col- 

 lapse of a large extent of breathing surface. Usually the mucus is 

 expectorated; that is, discharged through the nose. Thd matter is 

 coughed up, and when it reaches the larynx much of it may be swal- 

 lowed, and some is discharged from the nostrils. The horse can not 

 spit, like the human being, nor does the matter coughed up gain access 

 to the mouth. If in serious cases all the symptoms become aggra- 

 vated, the breathing is labored, short, and quick, it usually indicates 

 that the inflammation has reached the breathing cell^ and that catar- 

 rhal pneumonia is established. In this case the ribs rise and fall 

 much more than natural. This fact alone is enough to exclude the 

 idea that the animal may be affected with pleurisy, because, in pleu- 

 risy, the ribs are as nearly fixed as in the power of the animal to do 

 H. Doc. 795, 59-2 9 



