Tuberculosis. 



121 



sometimes extends into the air passages causing tuberculosis of 

 the larynx with a persistent paroxysmal cough and a harsh altered 

 voice. 



Tuberculosis of the udder. — A portion of a single quarter is 

 usually first affected, causing a circumscribed swelling, harder 

 than the rest of the gland, but not hot nor painful, and this grad- 

 ually extends to the whole udder. With this extension the 

 gland becomes harder, and the milk lessened, more watery and 

 clotted, and the lymphatic glands in front of the udder and be- 

 hind are enlarged, and hardened. The gradual advance of the 

 disease serves to disarm the milker of any suspicion and the milk 

 is commonly utilized until its watery or grumous appearance 

 draws special attention to the gland. The case may be tested by 

 inoculating with the milk, or less satisfactorily by a microscopic 

 search for the bacillus, or the tuberculin test may be applied. 



Tuberadosis of the lymphatic glands. — In cattle the lymphatic 

 glands are often found to be tuberculous to the exclusion of 

 internal organs, and as this form of the disease tends to become 

 chronic it is likely to be overlooked for a length of time. Wher- 

 ever a group of these glands exists, there may be tuberculosis. 

 In addition to those already cited may be here named : 



a. The submaxillary glands situated on the inner side of the 

 lower jaw at the point where the pulse is felt. These which are 

 almost imperceptible in their natural condition, may swell up to 

 any size, soften, burst, and discharge a cheesy matter. They 

 are most liable to be confounded with actinomysosis of the same 

 region but do not show the almost microscopic hard yellow clus- 

 ters of the actinomyces. They yield in place the specific bacillus. 



b. The glands at the root of the ear. — These swell in front or 

 behind the ear, soften and like the submaxillary glands they may 

 or may not burst and discharge. 



c. Glands inside the chest, mediastinal, bronchial, etc. — The 

 mediastinal and bronchial glands lying between the lungs in the 

 centre of the chest are often affected independently of the lungs, 

 and give no easily available symptom. A persistent nervous 

 cough and some unthriftiness, though on good, liberal rations^ 

 may arouse suspicion, but cannot lead to diagnosis. If the glafids 

 on the walls of the gzcllet {cesophagean) are implicated the vagus 

 nerve and stomach may be involved and digestion, rumination, 



