12G DISEASES OF THE RESPIRATORY ORGANS 



the former we hear a vesicular respiratory bruit, which has a hipping char- 

 acter, and the bronchial respiratory bruit, which is a Jjlowing murmur, 

 and, lastly, an indistinct respiratory bruit, which is a slight soft murmur. 



The vesicular respiratory bruit is heard when any portion of the lung 

 that is filled with air lies against the wall of the chest. In normal inspira- 

 tion the sound is a smooth, regular murmur, the air going directly into the 

 alveoli without any resistance. This sound can be increased very much 

 even during health by active movements or during excitement; it is also 

 much clearer and louder in emaciated animals where the walls of the chest 

 are thin. The vesicular murmur is always much louder in young animals, 

 and especially in puppies; the murmur is also noted in expiration in 

 animals under nine months. According to the amount of irritation, the 

 vesicular murmur is lessened in bronchial catarrh where there is much 

 swelling of the mucous membrane and secretions collected, in stenosis of 

 the upper air-passages, in emphysema of the lungs, in certain stages of 

 catarrhal pneumonia, in pleuritic or dropsical exudations, in thickening 

 of the pleura from the deposit of lymph-masses, tumors or oedema. 



It disappears entirely in croupous pleuritic effusions, in pneu- 

 mothorax, and in closure of one of the large bronchial tubes. 



The vesicular murmur is increased in dyspnoea in portions of the 

 lungs that are healthy when other parts are diseased, the healthy portions 

 doing all of the work; this is especially seen in bronchitis, where the 

 smaller bronchi are plugged up with secretions. We occasionally find 

 an irregular vesicular murmur in healthy dogs, but it is also heard in 

 cases of bronchitis; this murmur is heard only on inspiration. 



The murmur of expiration is very slight; in normal cases it can hardly 

 be heard; it is quite plain when the breathing is strong after excitement, 

 action, etc., especially in young dogs and those animals that have a thin 

 chest wall. According to the diseased condition, the sound is strength- 

 ened, varied in tone, and prolonged. 



The bronchial respiratory bruit (bronchial breathing, wheezing 

 sound) may be heard in the normal respiration of the pharynx, wind- 

 pipe, and the anterior part of the chest in diseased conditions; it appears 

 where any part of the lung is deprived of air, and the disease has plugged 

 up the smaller bronchi and extended to the larger-sized bronchi. This is 

 the case in the various pulmonary affections, where we find large sections 

 of the lungs are obstructed, or in compression of the lung by a pleuritic 

 exudate or by tumors, and in rare cases by the pressure of the diaphragm 

 where it is pushed forward from the collections of fluids in the abdomen. 

 It is also heard when a quantity of mucus is coming up the bronchial 

 tubes; this sound disappears when the mucus is coughed up. Lastly, 

 we find it in cases where the lung has large cavernous spaces in it. 



Indistinct respiratory bruits are heard in lobular pneumonia, where 



