BRONCHITIS 137 



produced by dragging on a collar, folloAv traumatisms, as in one case ob- 

 served, that is, fracture of the first rib on the left side, and it is also seen 

 following the pulmonary form of distemper. The treatment consists of 

 the application of a galvanic battery over the region of the recurrent 

 nerve, the administration of nux vomica internally, or of strychnia, 

 sulx'utaneouslv. 



DISEASES OF THE AIR-PASSAGES AND BRONCHIAL TUBES. 



Catarrh of the Windpipe and Bronchia; Bronchitis. 



{Trachitis and Bronchitis Catarrhalis.) 



Etiology. — Catarrh of the air-passages and of the bronchia occurs 

 very fretjuently in young, weakly, or debilitated dogs. It sometimes 

 originates primarily, but, as a rule, it occurs as a secondary disease. It 

 is caused by cold, especially by breathing cold air when the animal is 

 warm; and in pet dogs we see it cjuite often where the animals will lie 

 near the register or an open fire until they are very warm and then go to 

 the outside door and lie on the floor where the draught can strike on 

 them and so cool off very rapidly, and repeat this a number of times. 

 It is also caused by mechanical or chemical irritants, such as smoke, 

 dust, parasites, strong gases, or, secondarily, from the extension of in- 

 flammations from neighboring organs, as the larynx or lungs, or from 

 defective blood circulation of the lungs, produced by weakened heart 

 action. Catarrh of the trachea and bronchia is very often seen as a com- 

 plication of distemper, as well as many serious internal diseases, especially 

 in affections of the l:)rain. The latter condition is generally traced to the 

 fact that there is an accumulation of particles of food and secretions, 

 which collect in the mouth ami throat, decompose, and are respired into 

 the trachea and produce an irritation. 



There is no doul)t that infectious influences play a certain role in 

 the cause of this disease. 



Pathological Anatomy. — In describing any catarrh of the trachea it 

 should be classed under the head of bronchitis, as it is impossible to draw 

 the line of distinction between the two. In bronchitis the mucous mem- 

 brane is difi:"usely inflamed, swollen, and tears easily when touched. In 

 the ealier stages of the disease, there is little mucus found on it, but as 

 the disease goes on to the later stages the secretion becomes more copious 

 and turbid, purulent, and filled with pus corpuscles; later on it becomes 

 more or less colored with blood corpuscles. 



Chronic Catarrh. — In this condition, the color of the mucous mem- 

 Ijranc is l^rownish-grey, and the membrane is frequently uneven and 

 thickened; in circumscribed spots or covering the entire membrane the 



