222 PATHOGENIC BACTERIA IN MILK 



tions, gastro-intestinal disease, and scarlet fever in persons con- 

 suming the milk. Moore has also found streptococci in relation to 

 a number of diseases of cattle, sheep, and horses,^ as well as in 

 conditions of health. Klein, Kurth, Mervyn Gordon,^ and others, 

 have made attempts to work out a satisfactory classification of 

 streptococci, but up to the present it cannot be said that this is 

 yet accomplished. There is, however, a good deal of evidence in 

 support of the view that there is some causal relationship between 

 streptococcus and infectious mammitis.^ This affection of the 

 udder is, as is well known, an insidious condition, and gradual in 

 onset, sometimes becoming acute and epidemic, and at other times 

 of such mild degree as to be scarcely recognisable. Symptoms may 

 be marked or absent, and general or local, or both. Consequently 

 it is often impossible to diagnose clinically. The commonest signs 

 are some congestion, enlargement, and induration of the udder, and 

 the appearance of white casein masses in the milk. A microscopic 

 examination is generally necessary for diagnosis, and results in 

 finding pus cells and streptococci. Eastes found pus cells in 30 per 

 cent, of the milks which he examined, muco-pus in 48-7 per cent., 

 and streptococci in 75-2 per cent* An investigation of milk in St 

 Pancras in 1899 yielded 24 per cent, of samples containing pus 

 cells. Such milk generally has an acid reaction. Eastes, Hoist, 

 Niven, Stokes, Bergey, Hirsch, and others, have drawn attention 

 to the ill effects which streptococcal milk has upon persons con- 

 suming it. In the main these are twofold, namely, gastro- 

 intestinal diseases and sore throats. 



The evidence implicating streptococcal milk is empirical and 

 circumstantial, and yet it appears to be growing in force and volume. 

 On the other hand, streptococcus has been found in the fresh 

 milk derived from healthy udders. Reed and Ward^ have recently 



^ Moore, "Observations concerning the significance of Streptococci in 

 Comparative Pathology," American Vet. Rev., 1900, vol. xxiii. 



"^ See Reports of Medical Officer to Local Government Board, 1898- 1899 and 

 1 899- 1 900. 



^ Nocard and Mollereau, Archiv. Vet., 1884; Moore, "The Morphology, 

 Biology, and Pathogenic Properties of twenty-eight Streptococci found in 

 Investigation of Animal Diseases," Bureau of Animal Industry, Washington, 

 1893, Bull. No. 3. Hess, Landw. fahrb. der Schweiz, 2 Band, 1888 ; Nencki, 

 Ibid., 5 Band, 1891 ; von Freudenreich, Ibid., 7 Band, 1890; Guillebeau, Ibid., 

 4 Band, 1890, 5 Band, 1891, and 8 Band, 1894. 



* Brit. Med. four., 1899, ii., 1342. 



5 H. C. Reed and A. R. Ward, " Streptococci in Market Milk," American 

 Medicine, 14th February 1903, p. 257, 



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