704 ACUTE MAMMITIS 



(3.) ACUTE MAMMITIS. 



(A) INTERSTITIAL MAMMITIS. LYMPHOGENOUS MASTITIS. 



This disease affects the skin, subcutis, and interstitial connective 

 tissue. It generally starts from the teats, which in the cow very 

 frequently suffer from surface injuries, the rough hands of the milker 

 abrading the skin and possibly conveying infective material ; the 

 straw may also cause injury and infection. The micro-organisms 

 first enter the skin and subcutis and set up inflammation, which 

 generally extends to the capsule and the stroma of the gland. 



The process, therefore, seldom remains confined to one quarter, 

 but extends to several, or may even attack the entire udder. The 

 course of the lymph vessels of the separate teats, however, some- 

 times causes the disease to remain confined to single sections of the 

 gland. The skin and subcutaneous tissue are at first cedematous. 

 and later become infiltrated with plastic material ; slight exudation 

 of blood is not uncommon. We clearly have to deal here with an 

 acute inflammation, caused by infection through slight fissures and 

 cracks in the skin, particularly of the teats. The disease is probably 

 caused by pyogenic cocci or other microbes. Kitt produced the 

 disease in cows by infecting them with the bacillus of malignant 

 oedema. 



Symptoms and course. The condition is announced by a rise 

 in temperature of 2° to 5° Fahr., loss of appetite, cessation of 

 rumination, acceleration of breathing and circulation, constipation 

 and tympanites ; and locally by swelling and redness, which is 

 generally diffuse, and seldom limited to particular portions of the 

 gland. It appears suddenly ; the skin is injected, at first it appears 

 bright red, afterwards bluish. The swelling is then soft and 

 doughy, but later becomes hard and firm, and requires some force 

 to indent it. The skin is often exceedingly hot, but pain, as in 

 subcutaneous inflammation, is seldom severe, nor does the milk 

 show much change in quality, though the total quantity is greatly 

 diminished, and in the affected gland secretion may be arrested. 



In five to eight days the symptoms may gradually subside, the 

 redness and swelling disappear, and the secretion of milk return. 

 In other cases abscesses form. In or just beneath the skin, less 

 frequently in the superficial portions of the gland, several fluctuating 

 points develop, which after a short time break and discharge pus. 

 Such abscesses are distinguished from those occurring during 

 parenchymatous mastitis by their superficial position and small 



