940 Veterinary Obstetrics 



teat, are subjected to very great danger from acute infection. 

 In animals where extensive milk cisterns do not exist, like the 

 mare, and in carnivora, which have no cisterns at all, the tendency 

 to acute mammary infection is very much less. 



On the other hand, we find that in the carnivora, especially in 

 the bitch, without any milk cistern, there is a pre-eminent ten- 

 dency for the glands to become the seat of malignant new-growths. 

 When infection occurs in the capacious single milk cistern of a 

 ruminant, the entire quarter is almost inevitably involved. In 

 those animals with two or more cisterns, or with numerous milk 

 canals without cisterns, a single lobule of the gland may become 

 infected and the others remain sound. 



For convenience of description we may divide the diseases of 

 the udder into : (i) Acute Infections, (2) Chronic Infections, 

 (3) Wounds and Injuries, (4) Neoplasms. 



Acute Infections of the Mamm^h. Mammitis. 



Mastitis. 



Mammitis consists essentially of an infection of the mammary 

 gland, and, like the infections of other organs or tissues, may be 

 extremely variable in character. The different species of domestic 

 animals show great variations in their susceptibility to mammitis, 

 and in the type or types which the disease may assume. By 

 some authors, the inflammations of the gland have been divided 

 into catarrhal, phlegmonous and interstitial mammitis. Others 

 add to these, purulent and gangrenous mammitis. 



Until we understand better the exact nature of the various 

 forms of mammitis, especially in relation to the bacteriologic 

 cause of each, any classification which may be made is merely a 

 matter of convenience for purposes of description, which may 

 facilitate our understanding of certain more or less distinct types 

 of disease observed. 



The various species of domestic animals show such marked 

 differences in the prevailing type or types of diseases of the milk 

 glands that it is advantageous to consider those of each species 

 separately, although in many respects they may be identical. 



a. Mammitis or Mastitis in the Cow. 



The cow constitutes the chief dairy animal, for which purpose 

 she has been specially bred for centuries, and has been brought 



