CLINICAL DIAGNOSIS OF MASTITIS 121 



GENUINE TJDDER-INFECTIONS 



These infections are manifested by changes in the udder 

 and the milk. They may also be (ivided into acute and 

 chronic forms. 



The acute genuine udder-infections are streptomycosis, 

 staphylomycosis, and colibacillosis. They are severe in the 

 beginning, but are seldom fatal. Usually repair is estab- 

 lished by inflammation and sclerosis in a month. 



They are typical infections [parenchymatous mastitis] 

 and usually begin in one quarter, but may also spread to 

 other quarters by infection. Simultaneously with the in- 

 fection alterations in the milk occur. In severe infections 

 the milk is transformed into a serous, even red-stained, thin, 

 somewhat muddy fluid secretion. On the other hand it 

 may consist of thick yellow pus or a thick yellow mixture 

 of pus and milk. Slimy flakes of fibrin are frequently 

 present in the pus or altered milk. 



In addition to the changes in the milk a hard swelling 

 of the quarter occurs at the same time, which is at first 

 painful and later becomes painless and may vary to a high 

 degree. The corresponding lymph-gland is but slightly 

 or not at all affected. The condition usually begins with 

 fever, which subsides after a few days. Complications 

 with acute secondary infections and gangrene produce a 

 recurrence of fever and destroy the healing process. These 

 complications are rare, however. 



A specific clinical diagnosis of these affections is usually 

 impossible. 



One may suspect streptomycosis if the condition is 

 epizootic and affects a number of cows with a high fever 

 of short duration, and high or low grade disease processes 

 in the udders and milk. This is especially so when the 

 joints (tarsal joint) synchronously present a painful swell- 

 ing. If the condition is vigorous and severe or fatal, one 



