DISEASES OF GLAKD8 279 



Inflammation of the Mammary Gland (Mammitis— 



Mastitis). 



What are the causes of mastitis ? 



They are, in the vast majority of cases, of an infectious 

 nature, more rarely due to traumatisms and cold. 



Eow may infection reach the udder ? 



The infection may be of lymphogenous origin— that is, 

 reach the mammary gland through the lymph vessels; it may 

 bejgalactogenous, entering through the opening at the teat; 

 or it may be of hematogenous origin, reaching the gland 

 through the general circulation. 



Which is the most common way through which the infection 

 enters the udder ? 



Mainly through the opening at the end of the teat. 



Which bacteria and fungi are of practical interest in mas- 

 titis ? 

 The bacillus of tuberculosis, a number of specific mam- 

 mitis bacteria, botryomyces, actinomyces. 



Which varieties of mammitis are of practical importance ? 



Parenchymatous, catarrhal, acute interstitial, chronic in- 

 terstitial, purulent, gangrenous mammitis. 

 What? are the terminations of mastitis ? 



1. Resolution. Between the third and tenth day after the 

 outset of the inflammation of the udder, the more active 

 symptoms disappear, the swelling and pain become less and 

 the nature of the lacteal fluid once more approaches the nor- 

 mal in quantity and quality. 



Such prompt resolution is by no means frequent. In cows, 

 at least, mammitis has a chronic tendency. In these cases the 



