50-4 Tuberculosis. 



statistics of Copenhagen for 1895 showed that 29.7% of all slaughtered cattle 

 and over 10% of all swine were tuberculous. In the period beginning April, 1893, 

 and ending with the year 1908, 19,717 herds were tested with tuberculin. Of 

 these 11,553 were first tests. A total of 503,879 cattle were tested of which 108,378 

 or 21.5% reacted to the tuberculin test. During this period the number of reactors 

 was reduced from 40% to 8.5%*. Of 10,344 herds tested for the first time in the 

 year 1903, 2,664 herds (consisting of 33,946 animals) were found free from tuber- 

 culosis. Most of these herds contained less than 25 animals each; 153 herds were 

 composed of from 26 to 55 animals (Bang). 



In Norway, in 1895 to 1909, of 25,832 herds that were tested, 4,217 or 16.3% 

 were tuberculous. Of 219,925 animals tested 12,823 or 5.5% were infected (Malm). 



In Sweden, from 1897 to 1908, of 12,720 herds which were tested for the 

 first time, 5,527 herds were free from reactors. Of 306,372 animals tested 30.7% 

 reacted (Eegner). 



In Finland, from 1894 to 1900, of 75,447 cattle that were tested 13.7% 

 reacted (Hojer). 



Of the other European countries tuberculosis is very prevalent in Xorthern 

 and Central Italy, in .Spain and in Portugal. According to Nogueira the disease 

 exists to the extent of 3.8% among bulls which are reared in the open to supply 

 the market for bull fights. The disease is prevalent to an equal extent in Eussia, 

 Koumania, Servia and the Herzegovina. On the other hand the cattle of the steppes 

 of Eussia are practically free from the disease. Of 30,000 Servian cattle killed 

 annually in Budapest up to the year 1906, only .20 to .23% were found tuberculous. 



Outside of Europe tuberculosis occurs wherever European breeds of cattle have 

 been imported. Thus the disease is very prevalent in North America where, accord- 

 ing to Salmon, among suspected herds that were tested, 25% were found infected, 

 while among unsuspected herds 9% were found infected. Eeports of the Bureau 

 of Animal Industry show that of 400,008 cattle tested 9.25% reacted. According 

 to Melvin the disease causes an annual loss of $23,000,000 in the United States. 

 Tuberculosis is also quite prevalent in South America. In Buenos Ayres 3.7% 

 of all cattle and 10.8% of all swine were found tuberculous. In the State of 

 San Paoblo 20% of milk cows are tuberculous. Finally the disease is also prevalent 

 in Africa (Egypt and Southern Africa) as well as in Australia. In Japan where 

 tuberculosis has always been prevalent among human beings, it has been known 

 in cattle only for the past 30 years and since then has been gaining ground rapidly. 

 The disease was introduced by the importation of American cattle (Kanda). 



Etiology. The Bacillus Tuberculosis Koch is a slender, 

 slightly bent bacterium, 1.5-4.0 m. long and 0.3-0.5 m. in 

 diameter, which seems to be covered with a thin waxy substance. 

 It is non-motile and non-spornlating. In tissues it occnrs singly ; 

 in morbid secretions it is frequently found in groups, in parallel 

 bundles or in pairs placed at an acnte angle (see Fig. 77). In 

 rare cases it is composed of a chain of two or three links. In 

 fresh cultures it grows in wavy lines, while older cultures pro- 

 duce long threads which may show a tendency to branch and 

 form club-shaped swellings. Stained bacilli from morbid secre- 

 tions show colorless spaces which give them the appearance of 

 coccus chains. 



Besides the typical acid-fast form of the tubercle bacillus 

 there has recently been discovered by Much a non-acid-fast 

 granular form which consists of small granules arranged in 

 straight rows. This probably represents a young culture variety 

 of the species from which the rod shaped acid-fast bacterium 

 develops (see Fig. 78 and Fig. 79). The granular form which 

 is found especially in pearl disease of cattle and in cold ab- 

 scesses of man, is just as virulent as the acid-fast rod-like 

 species. 



By means of special staining methods the interior of the 

 tubercle bacillus reveals a granule (rarely two or four granules), 



