686 PATHOLOGY OF FARTURITIOX. 



an inflammation of the acini, but also of the intervening connective 

 tissue, involving the lymphatic system ; consequently, there is reason to 

 suspect the disease to be infectious. 



When circumscribed gangrene has occurred, and elimination of the 

 diseased part is accomplished, the dead mass may weigh as much as 

 five or six pounds in the Cow ; it is somewhat regularly oval, but 

 rather flattened and discoid in the Mare ; the colour is a light or pale 

 yellow, and in consistence it is pulpy but not elastic, and the finger 

 cannot be easily passed into its substance ; traces of its lobulated 

 structure can still be perceived, and if a section be made of it, all the 

 characters of the mammary gland can be made out in its interior. 



In diffused gangrene, however, the glandular tissue is deep-red in 

 colour, softened, and filled with pulpy cavities ; the ducts and sinuses 

 are distended or choked with coagulated milk, pus and serum, the 

 whole forming a diversely-coloured fluid. In the veins are sometimes 

 blood-clots, variable in colour and consistency ; gas and foetid fluids 

 escape from the tissue on section ; and the oedema is found to be due 

 to infiltrations of yellow serum in which are brown and greenish streaks. 

 This fluid, examined microscopically, has much the appearance of that 

 found in animals which have died from septicaemia. Shreds of necrotic 

 tissue are also met with. 



Causes. 



Mammitis appears to be due to the most diverse causes. Among the 

 principal predisposing causes, the first is lactation — the disease appear- 

 ing immediately before or soon after parturition ; and the animals whose 

 mammae are most active at this period, are those most frequently 

 attacked. In the great majority of cases in the Cow — in which animal 

 it is most serious — it follows within a month after parturition. It is 

 true that, in certain maladies— as foot-and-mouth disease, cow-pox, 

 sheep-pox, etc. — the udder may be afi'ected at any time ; yet the lacta- 

 tion period — that when the mammse are at the height of their function, is 

 the time when this inflammation is generally met with. With those 

 animals whose milk is only utilised to rear their progeny, sudden 

 separation from their young without any precautions is often noted as 

 an exciting or predisposing cause. The great activity of these glands 

 in the Cow, and the long time during which this activity is maintained, 

 is, there can be no doubt, one of the chief reasons why this animal 

 so often suffers from this affection. 



Mechanical causes may produce this inflammation — such as con- 

 tusions, wounds,^ injuries in milking- or sucking, blows from the head 

 of the young creature, etc. Parenchymatous inflammation of the gland 

 may also be due, according to Franck, to a deep purulent wound in 



^ Gotze (Sachs. Jahreshericht, 1867, p. 92), quoted by Franck, mentions an instance in 

 which the posterior part of the udder of a Cow became inflamed, and soon there was a 

 severe attack of mammitis. When the animal was killed, a large abscess was found in 

 the gland, and in it were two common pins which Gotze thought might have ptnetrated 

 there from the rumen. 



- In those countries where the milk of Ewes is utilised, like that of Cows, in the pro- 

 duction of cheese — as at Roquefort, where cheese bearing this name is largelj* manufac- 

 tured — mammitis appears to be very frequent, and has been attributed very often to the 

 rough handling the teats and udder receive in milking. 



Rnche-Lubin says that he has often witnessed shepherds acting so violently in milking, 

 that the Ewes could scarcely breathe, staggered in their hind-limbs, and sometimes fell 

 from the pain and shock. 



