6o STREPTOCOCCUS MASTITIS 



is of the first importance. Nbrgaard and Mohler found that 

 immunity may be produced in susceptible animals by the 

 filtrate of bouillon cultures, by sterilized bouillon cultures of 

 the specific streptococcus, and with the serum of artificially 

 immunized animals. 



REFERENCES. 



NoRGAARD AND MoHtER. Apoplectiform septicemia in chickens. 

 Bulletin No. 36, U. S. Bureau of Animal Industry , 1902. 



STREPTOCOCCUS MASTITIS. 



§46. Characterization. The term "streptococcus mas- 

 titis" has been given to an infectious disease of the udder of 

 cows caused by a streptococcus. It is characterized by hard 

 foci in the gland. 



§ 47. History. As early as 1848, Brennwold observed 

 in Switzerland an enzootic mastitis that was difficult to cure. 

 The affection was called "gelber Gait." Since that time this 

 affection has been found in nearly all if not all countries. 

 Among the more recent writers on this subject may be men- 

 tioned Hess and Borgeand in Switzerland, Nocard and Mol- 

 lereau in France, and Zschokke in Vienna. In America it 

 does not appear to have been studied independently of the 

 infectious form of mastitis described in § 17. The epizootic 

 mastitis occasionally reported in this country may be identical 

 with this supposed distinctively specific disease. Zschokke 

 found the streptococcus in 297 of the 444 cases of altered milk 

 examined. 



§ 48. Geographical Distribution. This affection has 

 been reported from nearly every country where cows are kept. 



§ 49. Etiology. The organism that causes this disease 

 was described by Kitt, as Streptococcus agalactia, and Guille- 

 beau as Streptococcus contagiosa;. It enters the udder through 

 the ducts of the teats. 



The writer has been unable to differentiate this strepto- 



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