TDBEECULOSIS 129 



Describe the tubercular mammary gland. 



The diseased process consists either of a localized tubercu- 

 losis, tuberculous mastitis or diffused miliary tuberculosis. 

 The bacillus rarely enters through the teat, thus creating a 

 primary tuberculosis ; in most cases it is of embolic origin — 

 that is, secondary. Such an udder, of which usually the 

 posterior quarter is at first diseased, shows a diffused, hard 

 swelling, which is little painful, with enlargement of the 

 regional lymph gland and supra-mammary lymph glands. 

 As the disease advances, hard nodules develop in the swollen 

 quarter ; finally the whole udder may attain a large size and 

 show the same symptoms just mentioned. In regard to the 

 lacteal fluid, it must be said that in the earlier stages it under- 

 goes no visible changes, only later it becomes watery and 

 flocculent, containing the specific bacillus. 



Describe tuberculosis of the lymph glands. 



The affected lymph gland enlarges and becomes hard, 

 explained by the process of calcification the tubercle under- 

 goes and the proliferation of the interfollicular connective 

 tissue of the gland. Infection of the lymph gland takes place 

 both by the blood and lymph vessels. 



Name the lymph glands most commonly involved. 



Those in the intermaxillary space and those near the 

 parotid gland, the retropharyngeal; those of the cervical 

 region, the prescapular, axillary, and those near the elbow, 

 the inguinal, popliteal and precrural, the supra-mammary 

 glands. Of the lymph glands of the internal organs, the 

 bronchial ones alone are of interest, as, by becoming enlarged, 

 they may compress the oesophagus and produce tympanitis. 



Describe tuberculosis of the shin and subcutis. 



This is but occasionally seen in cattle. They appear at 



