MUNICIPAL HYGIENE 691 



Catarrhal Mastitis. — This disease is, as a rule, confined 

 to one quarter of the mammary gland, and consists of an 

 inflammation of the milk sinus and ducts. On manipulation 

 there is a hardening at the base of the teat and around the 

 sinus, but not accompanied by any degree of pain or acute 

 symptoms, while the affected quarter presents no marked 

 enlargement. The disease runs a slow course, and it is 

 some time before the milk regains its normal condition. 

 Even for a time after recovery some thickening and indura- 

 tion remains in the lower portion of the gland. 



The milk drawn from the affected side at first shows no 

 apparent change, but if allowed to stand until the cream 

 separates it looks watery, almost translucent, while with 

 the cream appears to be a mucoid material. 



Microscopical examination of the milk reveals the 

 presence of leucocytes, epithelial cells, and a few strepto- 

 cocci. 



Malcolm, whose description we have literally followed, 

 tells us that though this condition of the gland may be due 

 to bacterial infection, dairymen have no doubt that it is 

 less frequent with careful competent milkers than with 

 incompetent. 



Acute Parenchymatous Mastitis is an acute inflammation 

 attacking two or more quarters or the whole gland. Well- 

 marked constitutional disturbance exists, with heat, swelling, 

 and pain of the udder. Suppuration soon follows the 

 occurrence of the disease, and a complete loss of the secret- 

 ing quarter, with subsequent atrophy, is a common sequel. 



In the early stages the milk is reddish-brown in colour, 

 and presents the appearance of a dirty flaky serous fluid. 

 On standing it separates into three layers, the precipitate 

 being casein, a reddish-brown whey existing as a middle 

 layer, and a mucoid greasy-like material on the top. 



Later on the milk becomes thicker, more or less purulent 

 in character, and eventually is little more than a thick 

 creamy pus. 



It frequently happens that more than one case of the 

 disease occurs at the same time, and this and other con- 



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