1 6 MASTITIS 



,,/•••, a Streptococcus (Fig. I ). It is, 



Ci^o*^^**"* »M however, difficult to distinguish 



. ^^^ ^.,^Vo /# 





■) 



between this affection and those 



• -« —■ •— ••. * •'^ . caused bv certain other bacteria. 





r, ^ ^ ^ ''o 2 I^ seems likely that many cases 



are primarily brought about by 



mechanical injuries which ren- 



. ^^ ^ - der possible the entrance into 



tl • \ ^ ® of the skin or of the milk ducts. 



••' Other ca.ses may be due to in- 



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



case of infectious mastitis. «. • u^ c i ■ i 



-^ -^ teria capable of producing, by 



means of their metabolic products, the inflammatory condition 

 without a distinct injury 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 bacteria to the secreting portions of the gland was not 

 well founded upon anatomical facts (Fig. 2). 



The acute and more chronic inflammator}' 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 

 frequently encountered as an infectious (transmissible) disease is 

 characterized by very marked changes in the milk accompanied 

 by the usual symptoms of parench^miatous inflammation of 

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

 tains flaky masses held in suspension in the clear or perhaps 

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

 blood-stained. The microscopic examination shows the pres- 

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

 corpu.scles. 



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 phlegniasics uteris. Streptococcus agalacticr coyitagiosce. 

 Staphylococcus mastitidis, Galactococcus versicolor, G.fulvus, G. albus. 



