Acute Mamniitis 941 



to a high state of perfection as a milk-producing animal. With 

 this specialization of function, there has arisen a vulnerabilitj^ of 

 the milk glands to injuries and diseases, which surpasses that seen 

 in any other domestic animal. We consequently meet with a 

 great variety of inflammatory diseases of the milk glands in 

 cows. These variations are due in part to the intensity of the 

 infection and the comparative power of resistance of the gland, 

 and are in large part due to the specific differences in the infec- 

 tions themselves. 



Mammitis in dairy cows has a wide economic and sanitary in- 

 terest. The pathologic milk of mammitis is usually rejected as 

 human food by the repulsive taste, smell or visible appearances. 

 Pathologic milk, unrecognizable by the special senses, like that 

 from a tubercular udder, may possess far greater danger for man. 



According to the avenue of infection, the inflammations of 

 the mammary glands may be divided into two groups, very un- 

 equal in size and importance : 



1. The infections which gain entrance into the cavit}' of the 

 milk gland from the exterior, through the milk orifice or orifices 

 in the teat, or through some wound involving the tissues which 

 constitute the walls of these cavities. 



2. A lesser group of infections, which reach the tissues of the 

 gland from some other portion of the body, through the medium 

 of the lymph or blood channels, e. g., tubercular mammitis. 



I. Acute Mammitis. Acute Mastitis. 



Acute mastitis may be defined as an infection of the milk 

 gland, due to the entrance into its substance of the micro-organ- 

 isms ordinarily inducing wound infection. We might liken 

 acute mammitis to wound infection itself, and regard the epithe- 

 lial lining of the milk cisterns, ducts or acini, or all these areas 

 combined, as representing the wound area which has become 

 infected. 



As in wound infection, so in acute mammitis, the infecting 

 agent may be of very diverse character. Investigators, in deal- 

 ing with acute mammitis, have found virtually all the types of 

 organisms which are recognizable in wound infection, such as 

 diplococci, streptococci, staphylococci and bacilli. 



In accordance with the clinical historv of wound infection, 



