414 • DISEASES OF CATTLE. 



those who have given this subject special attention, the udder be- 

 comes swollen uniformly and quite firm. This swelling, which is 

 painless, frequently attacks but one quarter, more rarely two, these 

 being usually the hind quarters. The larger milk ducts contain yel- 

 lowish, cheesy particles, in which are many tubercle bacilli. Later 

 larger nodules can be felt within the udder, which undergo the 

 various changes to which tubercles are subject. The udder may grow 

 very hard to the touch and become very large, weighing in some cases 

 up to 40 pounds. The milk, at first normal, becomes thin and watery 

 after a month or so, and is mixed with flakes and tubercle bacilli. 



As regards the frequency of the tuberculous processes in the dif- 

 ferent organs, the following carefully compiled statistics of the 

 disease in Bavaria and Baden may serve as a guide : 



Bavaria : Per cent. 



Tuberculosis of lungs and serous membranes 41 



Tuberculosis of lungs alone 33 



Tuberculosis of serous membranes alone (pearly disease) 17 



Tuberculosis of other organs 8 



Baden : 



Tuberculosis of lungs alone 21 



Tuberculosis of serous membranes alone _ 28 



Both combined 39 



Generalized tuberculosis 9 



Tuberculosis of the sexual organs alone 3 



Symptoms. — The beginning of the disease usually passes unnoticed, 

 inasmuch as it is very slow and insidious and rarely accompanied with 

 fever. When the lungs are involved a dull, short cough is noticed, 

 which may later on become prolonged, convulsive, and very trouble- 

 some to the animal. The cough is more frequent in the morning 

 after movement and drinking. The breathing varies. Only when 

 much of the lung tissue is diseased is it labored and accompanied 

 with active movements of the chest and nostrils. Discharge from the 

 nose is rare or absent. At times, however, when the tubercles have 

 broken down and cavities containing cheesy masses have formed in 

 the lung tissue, or when the air tubes have become filled with cheesy 

 and mucous masses, coughing will dislodge them and cause their dis- 

 charge. In advanced stages the breath may have a disagreeable odor. 

 Pressure on the chest wall may give rise to pain. 



The general effect on the body is at first slight. In fact, animals 

 may remain in good flesh for a considerable time. Invariably as the 

 disease progresses loss of flesh and appetite and paleness of the 

 mucous membranes become manifest. These sj^mptoms are accom- 

 panied with a gradual diminution of the milk secretion. The de- 

 bilitated condition of the animal is also manifested by a staring coat 

 and a tough, dry, harsh skin (hidebound). Digestive disturbances 

 are indicated by tympanites, or distention of the rumen by gas, colic, 



