Anatomy, Pathology and Histology of the Mammary Gland. 



normal milk secretion, (16 liters). A functional hyperemia in 

 the beginning of the lactation period increased the four quarters 

 uniformly to such an extent that a day after parturition the udder 

 touched the .ground with its central surfaces. 



Before and after parturition an abnormal amount of hy- 

 peremia occurs physiologically in the udder (hyperemia conges- 

 tiva). In inflammations the same condition may be present, the 

 capillaries are abnormally dilated, and greatly distended with 

 blood. This condition may result in the exuding of fluid and the 

 solid constituents of blood. These are known as capillary hem- 

 orrhages. In larger extensions of these hemorrhages they are 

 spoken of as suggilations, and when the blood is contained in a 

 sac-like cavity or swelling it is known as hematoma uberis. 



If in the congestive hyperemia the fluid constituents of the 

 blood pass into the tissue of the udder, it results in edema of the 

 udder. The same condition may develop as a result of hydremia, 

 as for instance after changing from dry to sloppy foods (Bang), 

 or as a result of multiple emboli of the blood vessels, or from a 

 varicose condition of the veins of the udder. 



Edema of the udder manifests itself as a soft or tense swelling of the tissue, which 

 retains the impression of the finger. While the teats usually remain normal on account 

 of their slight but dense connective tissue, quantities of fluid collect in the front of the 

 udder and between its glandular substance and the skin. 



The edema frequently extends posteriorly to the udder and up to the vulva. In- 

 fections of wounds with the bacillus of malignant edema may result in edema of the 

 udder. 



To those engaged in milk hygiene the most important of all 

 pathological conditions of the udder are the inflammations which 

 result from a reaction of the glandular tissue to any inflam- 

 matory irritant. In most instances the inflammations of the udder 

 are produced by microbian infections of various kinds, particularly 

 by poly-bacterial infections. The bacteria penetrate the udder 

 either by way of the blood circulation or from the outside through 

 the orifices of the milk ducts. In such cases it is spoken of as a 

 hematogenic or galactogenic mode of infection. If the infection 

 results from a mixture of bacteria, and is not caused by one kind 

 alone, the affection is a mixed infection. The infection may result 

 from traumatic conditions when injuries extending into the paren- 

 chyma of the glands make the infection possible, or from galactif- 

 erous-traumatic causes when the infectious material enters the 

 milk cisterns upon milking tubes or straws. The infection may 

 take place also through simple contact of the orifice of the teat 

 with the infectious material. Thus the different forms of mastitis, 

 the peracute, acute or chronic inflammations of the udder may 

 arise, depending upon the character of the infectious material and 

 upon special accessory conditions. 



The possibility of galactiferous infection was first experimentally proven by Frank. 

 The character and the varieties of inflammations of the udder were further established 

 .by the work of Kitt, Nocard and Mollereau, Lucet, Bang, Hess and Borgeaud, Guillebeau. 

 Zschokke, Sven Wall, and others. 



