gg Internal Influences on the Character of Milk. 



occurrence of specific disease agents in milk, and it is known that 

 these pass into the milk either directly from the blood being then 

 eliminated with the milk, or else they reach the milk through sub- 

 sequent contamination of the milk with excretions. 



A rapid diminution of the milk yield is characteristic in all 

 acute diseases associated with great pain and fever, and in some 

 cases a sudden cessation of the secretion may be observed. 



Whenever the yield of milk of a cow suddenly shows a con- 

 siderable diminution, all of her milk should be excluded from mar- 

 ket, even though the animal shows no visible affection and before 

 the disease can be recognized as a general or specific affection. In 

 the sense of the pure food law the milk of every severely affected 

 cow should be considered unfit for food without any further con- 

 sideration. 



Sometimes this unfitness of the milk is manifested by strong 

 objective perceptible changes, as compared with the secretion of 

 healthy animals. 



The milk may become bitter, salty, have an increase of ash and 

 albumin, and coagulate more rapidly than healthy milk (Jensen). 

 The fat content of the milk is at the same time diminished or in- 

 creased, while the sugar and ash contents may show fluctuation. 

 The amount of catalase present, according to Spindler, may in- 

 crease considerably, especially in cases of peritonitis and tubercu- 

 losis. The reaction of the milk remains acid or becomes slightly 

 alkaline. According to Schnorf, most of the internal affections, 

 even when the udder is not involved, produce a diminution of 

 sugar and proteid contents as a result of increased metabolism. 

 The electrical conductivity of the milk of animals with general 

 affections is subject to great fluctuations. After tuberculin injec- 

 tions with subsequent fever, the milk shows a slight increase in 

 its electrical conductivity. The index of refraction in pathological 

 milk is normal, and not diminished; the temperature at which 

 freezing occurs is not infrequently higher. 



During the course of individual diseases the following should 

 be considered: 



An elimination of toxins and toxic products of metabolism 

 with the milk is to be feared in all septic and pyemic diseases. If 

 with this there is a possibility of contamination with pathological 

 excretions, as for instance in septic metritis, hemorrhagic or 

 ichorous enteritis, or in the retention of putrid afterbirth, the milk 

 should be considered harmful. In septic metritis the infective 

 agents pass from the uterus into the meat and into the udder, from 

 which they may be eliminated. Basenau demonstrated the Bacillus 

 morbificans bovis, a meat poisoning organism of the colon typhoid 

 group, in the meat during the existence of septic metritis. The 

 stapylococci and streptococci which are frequent participants in 

 mixed infections of the uterus, are also eliminated with the milk, 

 provided the udder has not already ceased its secretion. 



