BOVINE TUBERCULOSIS -zyr 



and calcareous degeneration as compared with caseation in tuber- 

 culosis of man. 



Tuberculosis of the udder is comparatively rare. Out of lOO 

 tuberculous cows not more than 3 or 4 have tuberculosis of the udder 

 (Bang). The disease occurs as a diffuse, slightly hard, enlarge- 

 ment, generally unaccompanied by fever or tenderness of the organ. 

 Usually only one quarter is attacked, and that generally a posterior 

 quarter. The gland lobules become hypertrophied, and the larger 

 milk-ducts contain yellowish caseous masses, full of bacilli. As 

 the condition advances, there is a considerable increase of the 

 interlobular connective tissue (interstitial mastitis) of the nature of 

 a sclerosis, and firm tubercles of various sizes begin to appear. 

 Consequent upon these changes the udder becomes nodular, and 

 hard and tough. Miliary tubercles appear in the walls of acini, 

 and enormous deposits of bacilli may be found in the udder. 

 Simultaneously with these changes, the mammary lymphatic 

 glands (pudic glands) lying above the posterior region of the 

 udder became enlarged, indurated, and caseous. The disease may 

 advance slowly or with great rapidity. But finally the condition is 

 such that the glandular tissue of the udder is, as it were, smothered 

 by the hypertrophy and fibrous transformation of the interstitial 

 connective tissue. The large excretory ducts become blocked by 

 granulations or fibrous growth outside them, or by caseous masses 

 inside. This stage inevitably leads to milk suppression. 



It should not be forgotten that tuberculosis of the udder is 

 associated with tuberculosis of the internal organs. It is almost 

 invariably secondary. It may exist with mild or advanced disease 

 of the internal organs. Its diagnosis is all the more difficult owing 

 to the fact that there may be no symptoms. Generally, opinion 

 must be guided by the local condition of the udder coupled with 

 the condition of the milk. It may occur as a slow, painless growth 

 only evident when advanced, or it may increase with extraordinarj' 

 rapidity. This latter fact makes it desirable that every animal 

 suffering from tuberculosis of however mild a character should be 

 strictly eliminated from dairy stock. The three points usually 

 emphasised for diagnosis of tuberculous udder disease are — {a) 

 abnormal milk from one quarter, generally a posterior quarter ; 

 if}) some hardness, toughness or irregularity of the udder ; and {c) 

 enlargment of supra-mammary glands.^ The best diagnostic of 

 general tuberculosis is the tuberculin reaction. 



^ See also Report of Royal Commission on Tubetrulosis., 1896, part iii., pp. 



41, 42. 



