94 MILK HYGIENE 



udder tissue and agalactia. More rarely, streptococci 

 occur as causative factors of a mild catarrh of the udder. 



2. Stapliylococci, which sometimes cause a milder 

 form of udder catarrh, and sometimes cause a light 

 or moderately severe parenchymatous inflammation, 

 which may end in recovery, in abscess formation or in 

 contraction of the udder. The Staphylococcus pyogenes 

 aureus and albus are found, but others occur as well. 

 In this group, as is known, the differentiation is 

 difficult. 



3. The colon group. The parenchymatous forms of 

 mastitis caused by organisms of this group may be mild, 

 medium or severe, and they may end in spontaneous 

 recovery, necrosis, gangrene and formation of abscesses, 

 or in induration. The systemic manifestations may 

 be very marked, and the infection may even result 

 fatally. 



It is impossible to determine by clinical signs which 

 bacteria are present. In order to decide this, it is 

 necessary to resort to microscopic and bacteriological 

 examination. 



It is important for us to note that streptococcus 

 forms of mastitis not infrequently appear as a con- 

 tagious disease and little by little extend to a large pro- 

 portion of the cows of the herd. It is also important to 

 note that streptococci in certain forms of mastitis may 

 continue in the secretion after the principal clinical signs 

 have disappeared, and are able to again cause a breaking 

 out of inflammation of the gland when lactation begins 

 anew. 



The admixture of pus gives the milk a most unappe- 

 tizing appearance, often causes an unpleasant taste and 

 frequently causes it to putrefy quickly, or to curdle. On 

 this account, it is necessary to prevent the mixing of the 

 secretion from infected glands with the other milk. Be- 



