98 Tuberculosis. 



tubercle bacilli without the udder indicating any special lesions, 

 and without the milk showing any noteworthy changes. 



The quantity of the secretion from a tuberculous quarter is at 

 first uninfluenced, or only slightly so ; later it is considerably dimin- 

 ished. For a long time* it is of a normal appearance ; later it 

 generally becomes thick, transparent, watery, intermixed with small 

 flakes, or again it may become thick, yellow, pus-like, depending on 

 the intensity and extension of the lesions in the udder and the in- 

 fluence of the general health of the cow. 



Tuberculosis of the udder as a rule is of an embolic character, 

 and rarely represents the result of a galactiferous infection. No- 

 card, Meyer, Calmette and Guerin, and Zwick succeeded in pro- 

 ducing tuberculosis of the udder of various characters, by injections 

 of bovine and human tubercle bacilli into the milk duct of the teats. 

 The pathologico-anatomical appearance in these instances was the 

 same. 



The extent of the spread of tuberculosis in cattle in general is 

 best indicated by the statistics of abattoirs in the different states. 



In Germany in 1904, 17.89%, in 1905, 19.16%, in 1906, 20.66%, 

 and in 1907, 21.21% of cattle were retained on account of tuber- 

 culosis, and 0.26%, 0.30%, and 0.35%, respectively, on account of 

 tuberculosis of the udder. In Bavaria in 1898, 5.7% ; 1900, 6.0% ; 

 1902, 6.8%; 1904, 9.2%; 1906, 10.31%, were tuberculous. 



The spread of tuberculosis is especially assisted by exposure 

 in stabling (in 1907, 7.28% of young stock, 18.54% bulls, 22.55% 

 steers, and 29.62% of cows were found to be tuberculous on 

 slaughter, against 5.3%, 13.9%, 18.3% and 25.3%, respectively, 

 in 1904), and forced feeding while the percentage in pasture ani- 

 mals diminishes considerably, and in range cattle tuberculosis is 

 practically unknown. In Prussia the total infection from 1898 to 

 1906 is estimated at 16.09 to 23.4%, in Saxony from 30.46 to 37.58%, 

 from 1898 to 1908. In France in certain localities the infection ex- 

 ists in 30 to 40% of the stock, an average of 10%. In other 

 countries similar conditions obtain. 



If the abattoir findings are not considered as indicative of real 

 conditions, and delicate biological methods are employed which 

 prove that an animal is infected with the tubercle bacillus (with- 

 out however manifesting anatomically demonstrable changes) the 

 increase of the numbers is considerable. 



In Saxony from 1891 to 1897, in round numbers two-thirds of 

 the cattle were found to be infected through the aid of tuberculin. 

 Ostertag accepts 25% of the cattle as infected in northern Germany 

 and around Stuttgart, basing his estimate on sample testing in the 

 various localities. In France from 50-80% of the animals reacted, 

 in Great Britain 27%, in Austria 14-60%, in Hungary up to 35 . 18%, 

 Belguim 48.8%, Norway 22.8%, Sweden about 31%, Finland 

 13.7%. In Denmark during the first years of the tuberculosis 

 eradication 38.5 to 40% of the animals gave tuberculin reactions, 

 while later only 8.5% reacted. 



