1 6 MASTITIS 



^••.^ a Streptococcus (Fig. i). It is, 



<~p ->.■'' •••••^ ^ however, difficult to distinguish 



^ '' -a- ' V'" -, • ^ between this affection and those 



caused bv certain other bacteria. 



\ / c,\^' ^^.^ ! It seems likelv that man3- cases 



^ cj •*"***•, I ■ ,.••••♦.•* are primarily' brought about bj- 

 C) ; .;*» • *• •** ,.•••,. mechanical injuries which ren- 

 » \ t <^ ••* ••••• der possible the entrance into 



" ****V \ ^ ° ' '■^'^ fresh tissues of the bacteria 



(||l • \ O - of the skin or of the milk ducts. 



.••* Other cases maj' be due to in- 



FiG. I. Streptococcus fyom a faction through the teat of bac- 

 case of inffctioH, mastitis. j^j.;^ capable of producing, by 



means of their metabolic products, the inflammatory' condition 

 without a distinct injur5' to the mucous membrane. The for- 

 mer view that there was a sphincter muscle near the base of 

 the teat which closed the duct sufficiently to prevent the en- 

 trance of Ijacteria to the secreting portions of the gland was not 

 well founded upon anatomical facts (Fig. 2). 



The acute and more chronic inflammatory affections of the 

 udder fall very naturally into two groups, namely, ( i) those in 

 which the parenchyma is most affected and (2 ) those in which the 

 stroma or fibrous tissue is involved. The form of mastitis more 

 frequentlv encountered as an infectious (transmissible) disease is 

 characterized by very marked changes in the milk accompanied 

 by the usual symptoms of parenchymatous inflammation of 

 the gland itself. The discharge from the udder usually con- 

 tains flak3' masses held in suspension irr the clear or perhaps 

 cloudy serum. The color varies, and occasionally the mass is 

 blood-stained. The microscojnc examination shows the pres- 

 ence of agglutinated fat globules, pus cells, and of ten red blood 

 corpuscles. 



A number of bacteria* considered of more or less etiological 



*Among the bacteria which have been found in udder trouble and 

 described as the possible or perhaps the more probable cause the follow- 

 ing species may be mentioned : 



Bacterium phlegniasice uteris. Streptococcus agalactice contagiosa:, 

 Slap/iylococcus mastitidis, (ralactococcus versicotor, G./ulviis, G. albus. 



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