692 VETERINAEY HYGIENE 



siderations suggest bacterial infection as the prime cause, 

 the organism gaining access to the gland through the teat- 

 duct. 



Subcutaneous or Interstitial Mastitis is an acute inflamma- 

 tion of the subcutaneous and interstitial tissues usually 

 affecting the half or whole of the udder, and characterized 

 by heat, pain, and marked swelling. There is slight con- 

 stitutional disturbance, but no alteration in the character 

 of the milk, though the quantity may be diminished. 



Such cases, often attributed to cold, are probably the 

 result of skin infection through some injury. 



Traumatic Mastitis is the result of external violence, 

 especially in cows with large udders. The degree and 

 severity of the attack depend upon the extent of the injury ; 

 the formation of small subcutaneous abscesses is by no 

 means uncommon, and where the gland structure is not 

 involved no alteration in the character of the milk occurs. 



Specific Contagious Mastitis is a well-recognised condition 

 recorded by Malcolm and others. Besides slight constitu- 

 tional disturbances there is a rash on the base of the teats, 

 and tumefaction and induration of the gland structure sur- 

 rounding the milk sinuses, with pain on pressure. 



There is a marked reduction in the quantity of milk, 

 which in appearance is of a dirty yellow colour, containing 

 curdled stringy clots. 



In an outbreak recorded by Eadway* the milk after 

 standing separated into a thin layer o£ cream, a flocculent 

 deposit, and an intervening bluish layer of fluid ; the fluid 

 also had an odour resembling decaying vegetable refuse. 

 In this particular outbreak the milk gave the first indication 

 of something being wrong ; it was not until later that 

 hardening of the affected quarter and base of the teats 

 occurred, and no rash at any time appeared. 



From observations made by Riddocht the incubative 



* 'Contagious Mastitis in Cows': Mr. C. Eadway, M.E.C.V.S., 

 Journal of Comparative Pathology, vol. xv., part iv., 1902. 



t ' Contagious Mastitis in Dairy Cows ' : Mr. John Biddoch, 

 M.E.C.V.S., Journal of Comparative Pathology, vol. xv., part iv., 

 1902. 



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