574 DISEASES OF THE MAMMARY GLANDS. 



become infiltrated and large numbers of leucocytes are poured forth 

 around the glanduUir culs-de-sac. 



The tissues being thus affected, the virulent organisms penetrate 

 from the acini into the interstitial tissue, and from this time onwards 

 the lesions become mixed. 



Inversely, should infection originate in the lymphatic spaces, a 

 time arrives when the organisms make their way from the interstitial 

 tissue into the acini, with a similar result in the end. 



The development of the lesions may be arrested or may pass on to 

 suppuration, or even gangrene, of the parenchymatous lobules. Cases 

 happen in which infection is so rapid and severe that the successive 

 stages cannot even be identified, and gangrene appears without any pre- 

 liminary stages at all. Lucidly the commonest forms are less serious. 



Symptoms. Acute mammitis is characterised by its sudden appear- 

 ance, more or less acute general symptoms (dulness, fever, and loss 

 of appetite), and variable local symptoms. When the practitioner is 

 able to follow the development of the disease throughout, he may 

 sometimes distinguish well-marked signs, which permit the two clinical 

 varieties to be distinguished. 



A. Interstitial Mammitis. — This form, which might perhaps also 

 be termed peri-mammitis when it primarily affects the subcutaneous 

 lymphatic spaces, has also received the names of phlegmonous and 

 lymphogenous mammitis. 



It is characterised by alarming general symptoms, and particularly 

 by a rise in temperature of 2°, 4*^, or even 5° Fahr., with all its con- 

 sequences, such as loss of appetite, stoppage of rumination, acceleration 

 of breathing and circulation, slight tympanites, constipation, and by 

 the thrusting of the hind limb on the affected side away from the 

 centre line. The animals groan when forced to move. 



These symptoms sometimes precede by a considerable interval the 

 appearance of the local changes, which consist in painful swelling of 

 one or two quarters, rarely of more. 



The peri-mammary subcutaneous tissue is infiltrated, cedematous, 

 painful on palpation and preserves the imprint of the finger. The teat 

 is tense, swollen, very tender, and of reddish colour. In the grave 

 forms the swelling extends forwards under the abdomen in the direc- 

 tion of the umbilicus, and backwards towards the perineum. The local 

 temperature is abnormally high, the secretion of milk in the diseased 

 gland is modified or checked, and sometimes this phenomenon extends 

 by reflex action to the neighbouring quarters, although the latter may 

 not themselves be affected. The inflammation rarely extends from one 

 quarter to another, because the lymphatic plexuses do not anastomose 

 (Fig. 237). 



