Ostertag's Method. 



other hand the requirements have been accentuated in cases where 

 favorable considerations prevailed. Thus for instance in a herd in 

 which only a few animals react it would be advisable to dispose of 

 them without further consideration, and after a thorough disinfec- 

 tion of the stable the defensive work against tuberculosis may be 

 instituted, through the introduction of only non-reacting cattle, 

 and by the disposing of all animals which prove tuberculous on 

 the following tuberculin tests. 



The Siedamgrotzky-Ostertag method consists of immediate 

 disposition of all animals with open tuberculosis (by this means 

 the animals eliminating tubercle bacilli are excluded), and in 

 bringing up the calves free of tuberculosis by feeding them with 

 pasteurized milk or with milk from healthy cows. The calves are 

 subjected to the tuberculin test after they are weaned, and the re- 

 acting animals are not bred. The herds which are included in this 

 method of eradication are subjected semi-annually to a clinical 

 examination, and the clinically suspected animals are removed and 

 disposed of. Further than this, the mixed milk of the herd, as well 

 as the suspicious secretions and excretions are examined 

 bacteriologically. 



The results of the Ostertag eradication method of course can 

 not be compared with that of Bang. Since there are retained in 

 the herd all tuberculous animals which show no clinical form of 

 tuberculosis, or in which there is a suspicion of open tuberculosis 

 but whose secretions and excretions fail to reveal the presence of 

 tubercle bacilli. Therefore a constant danger of infection for the 

 animals free of the disease prevails, as tuberculosis may at any 

 time develop into an open form. But since it is required that the 

 calves should be brought up free of tuberculosis, and that the elim- 

 inators of tubercle bacilli should be determined by periodical clin- 

 ical examinations as well as by the testing of the entire mixed milk 

 of the herd and the individual secretions and excretions of sus- 

 pected animals, Ostertag has obtained relatively very good results, 

 where his requirements have been conscientiously carried out. 



This method has an advantage in that the stock owners who 

 offer great objections to radical methods of eradication on ac- 

 count of the immediate economic losses which they entail, are will- 

 ing to work intelligently and with pleasure with a system of eradi- 

 cation such as is offered by Ostertag's method. 



This assertion is best proven by the tabulation of Bautmann, which shows the in- 

 creasing popularity of this method. The method was voluntarily adopted in the fol- 

 lowing cases: 



1903-1904, 1,457 animals; 1904-1905, 1,372; 1905-1906, 5,333; 1906-1907, 5,395; 

 1907-1908, 5.193; 1908-1909, 8,839; 1909-1910, 18,822; and 1910-1911, 19,828 animals. 

 The following data illustrate the results obtained with the method: 

 Open tuberculosis was present in the province of: 



East Prussia n 1900 in 2.7 % out of 10900 examinations 



East Prussia ; n 1904 in 1.3 % out of 17500 examinations 



Pommerania n 1902 in 2.93% out of 8808 examinations 



Pommerania n 1906 in 0.6 % out of 22356 examinations 



Brandenburg m 1903 in 3.46% out of 5200 examinations 



