Tuberculosis. 117 



into a dead cheesy mass but develops into firm fibrous rounded 

 nodules hanging in clusters from the lungs, inside of the ribs, or 

 skin, and known as pearl disease (perl-knoten), grapes, etc. This 

 form is particularly common in cattle. In man may be found 

 nearly all forms of the disease, the primary hard red congested 

 nodule, the same with its grayish disintegrating centre, the firm 

 caseated mass, the same further softened into a white or yellowish 

 semi-liquid pus-like mass, and in addition an open unhealthy 

 sore caused by the breaking down of the tuberculous growth on 

 the skin (lupus), or intestine, etc. Similar tuberculous sores are 

 found on the skin or mucous membrane (bowels, throat) of cattle 

 and other animals. In all the many forms and seats of the dis- 

 ease the bacillus may be found in the affected parts, and the 

 morbid discharges from the lungs, skin, open sores, etc. 



Symptoms in Cattle. 



a. Tuberculosis of the lungs. — In the chronic cases which are 

 by far the most common this may last for months and years un- 

 perceived ; in acute cases it may prove fatal in a month. 



In recent, slight, chronic cases there may be no other ground 

 of sus^iicion than an occasional cough when the animal leaves the 

 hot stable for the cold outer air, when it is suddenly raised in the 

 stall, when it is run for a short distance, when it drinks cold 

 water or eats dusty food. The cough is usually small, dry, 

 wheezing, and may be repeated several times. When run or 

 driven rapidly the animal proves short winded. Yet it may show 

 as good spirits, as clear, full an eye, as smooth glossy a coat, as 

 supple and mellow a skin, as good an appetite, as rich and abund- 

 ant a flow of milk, and as much propensity to fatten as its healthy 

 fellows. An accomplished diagnostician may detect altered 

 sounds on percussion and auscultation of the chest, but from the 

 difficulty introduced by the heavy muscular shoulder, the frequent 

 variations in the size of the heart, the rumbling and crepitating 

 sounds from stomach and bowels, which, according as they are 

 full or empty, press forward and dimish the size of the lungs, and 

 greatly mask or modify the results, even the able practitioner can- 

 not be trusted to detect these, and the case fails to be recognized. 

 There may be a flow from the nose in which bacilli should be 

 detected by the microscope, but cattle have a habit of cleaning 



