IMPORTANCE TO MILK CONTROL 139 



In acute udder-infections where the changes in the milk 

 occur simultaneously with those in the udder, these rules 

 are easy to follow. These infections may be recognized by 

 the attendants without the assistance of a veterinarian. 



The udder is considered healthy when it is no longer 

 swollen and hard, and when the milk of a sample milking 

 presents a completely normal appearance and contains no 

 fibrin or pus flakes. This test is carried out by the 

 veterinarian. 



In typical chronic infections the above rules are difficult 

 to observe, since the milk in these infections retains its nor- 

 mal appearance weeks or months after the infection has 

 taken place. The acute infections can be recognized by 

 the attendants while, on the contrary, the typical chronic 

 cases can only be diagnosed by the veterinarian. 



If a milk-test record is kept, one can take note of all 

 cows which show a premature and rapid diminution in milk 

 secretion and then examine their udders and in this way, 

 perhaps, make a timely diagnosis. If no milk record is 

 kept one is compelled to examine all the udders. 



The examination is best made after milking, when the 

 udders are relaxed and collapsed. In this condition a swell- 

 ing or thickening is more easily determined. The udder is 

 inspected from behind and from both sides. If lesions are 

 observed in this way a closer examination of the udder is 

 made. The lesion is palpated, as are the lymph-glands, 

 and if a chronic condition is suspected in the udder examina- 

 tion of a milk sample is ordered. 



The milk sample should only be taken from the dis- 

 eased quarter. A microscopic examination of the sediment 

 of the milk sample confirms or contradicts the tentative 

 diagnosis. 



If a chronic udder-infection is diagnosed one is gov- 

 erned by the rules designated, except in udder-tuberculosis, 

 in which condition the animal must be slaughtered as unfit 



