DAIRY INSPECTION 157 



the teat and if the stream is split or deflected from the 

 normal direction. 



Palpate the supramammary lymph-glands. Stand- 

 ing in the rear of the cow, press the hand forward along 

 the upper and posterior margin of the udder, with the 

 thumb on one side of the median line and the fingers on 

 the other, and grasp the glands by bringing the fingers 

 and thumb together. Ordinarily, these glands are about 

 2 inches in diameter, but in heavy milkers they may be 

 larger. 



Pronounced swelling, excessive heat, and pain in one or more 

 quarters of the udder, with marked changes in the milk, are 

 symptoms of parenchymatous mastitis. 



Firm nodules which are neither hot nor painful, or a rather 

 diffuse induration which is painless and without heat, in one or 

 both posterior quarters, with enlargement of the supramam- 

 mary lymph-glands, are symptoms of tuberculosis of the udder. 

 There is no apparent alteration of the milk during the first 

 stages of the disease. Indurated areas of greater or less extent 

 result also from parenchymatous and catarrhal mastitis, but 

 they are not accompanied by enlargement of the lymph-glands, 

 except in the acute stage. 



Enlargement of the supramammary lymph-glands is asso- 

 ciated with tuberculosis of the udder and also occurs during 

 acute mastitis. These glands may be enlarged as a result of 

 tuberculous infection when no symptoms of the disease are 

 apparent in the udder. 



Difficulty in expressing milk from the teat and deflection 

 or division of the milk stream are early symptoms of catarrhal 

 mastitis. If pus or mucus can be squeezed out of the teat 

 canal, catarrhal mastitis is present. A scab may be found over 

 the opening of the teat canal when this disease exists, although 

 clots or flakes of dried milk are sometimes present when the 

 udder is normal except for some defect in the sphincter ap- 

 paratus of the teat. The milk may appear unaltered or show 

 only slight changes when these symptoms are present. 



