INFLUENCE OF DISEASE UPON MILK 109 



the udder and is usually caused by the Bacillus phleg- 

 masia uberis or other varieties of colon bacilli, sometimes 

 by organisms of the paracolon or paratyphus group, the 

 enteriditis bacillus or by staphylococci. Septicaemia may 

 develop in the course of the disease. Severe cases may 

 terminate in gangrenous mastitis. In the beginning of 

 the disease, and throughout mild cases, a turbid fluid 

 resembling whey in appearance and containing flakes of 

 casein, is obtained from the affected quarter. Later, in 

 cases of medium degree, the fluid resembles serum and 

 contains clots of fibrin. In the more severe cases, the 

 secretion is discolored with blood. In gangrenous mas- 

 titis, a small amount of bloody-serous, dark, foul-smelling 

 fluid, which contains gas bubbles, may be obtained from 

 the affected quarter. The chemical changes which occur 

 in the milk in parenchymatous mastitis are similar to those 

 which take place in catarrhal mastitis. There is a de- 

 crease in the lactose, which is sometimes entirely absent ; 

 the fat is usually decreased, although sometimes it is in- 

 creased; the casein is decreased, while the albumin, glob- 

 ulin, and salts, especially sodium chloride, are increased. 

 The taste is salty or bitter. There is an increase in the 

 content of catalase and coagulation takes place when the 

 alcohol or boiling test is applied. 



3. Interstitial Mastitis. The simple, traumatic form 

 of interstitial mastitis, in which the inflammatory process 

 is limited in extent and rather mild, has no important 

 effect upon the milk secretion, but when the disease is 

 due to the entrance of bacteria through fissures or 

 wounds, as is most frequently the case, a phlegmonous 

 inflammation occurs in the subcutaneous or interstitial 

 connective tissue which is accompanied by a rise of the 

 body temperature, sometimes to 107 F., and other symp- 



