Prognosis, Treatment. 59 j^ 



animals in question liernmnently cease to react to the tuberculin 

 test. 



Although the possibility of recovery from tuberculosis has 

 thus been demonstrated the course or final termination of the 

 disease cannot be predicted even with a degree of probability. 

 In general, favorable surroundings, especially pure fresh air, 

 good food and care, moderate exercise and middle age have 

 a favorable influence on the course of the disease. Not in- 

 frequentty, however, the disease makes rapid strides toward 

 a fatal termination in spite of favorable external conditions. 

 Under opposite conditions a gradual spread of the morbid 

 process is the rule and the unfavorable effect of hard work in 

 this respect is well demonstrated by the frequency of advanced 

 tuberculosis among the otherwise naturally tough working oxen 

 of the range breeds of Europe. The unfavorable course of 

 the disease in these cases is no doubt also associated with the 

 fact that these animals, when kept with infected herds, are 

 almost continually exposed to infection and reinfection, result- 

 ing in aggravation of already infected centers and in the pro- 

 duction of new areas in healthy organs. 



According to the intensity and the frequency of reinfections 

 the disease advances with increasing certainty to its fatal ter- 

 mination. When clinical symptoms have made their appearance, 

 recovery may be considered as entirely out of the question. 



Treatment. Since the incurability of tuberculosis of do- 

 mestic animals, after clinical symptoms have made their ap- 

 pearance, has been recognized from time immemorial, serious 

 attempts to bring about recovery are hardly ever made in recent 

 times. The immediate use of evidently affected animals for food 

 purposes has now been generally accepted as the best method 

 of dealing with this problem. In human medicine, also, in spite 

 of numberless attempts in this direction, reliable curative 

 methods are unknown. On the other hand, careful observations 

 made in recent years have shown that favorable hygienic con- 

 ditions, especially living in pure fresh air, nutritious food and 

 physical rest may check the progress of the disease in the early 

 stages and not infrequently bring about a cure. Similar con- 

 ditions would probably have the same favorable effect in ani- 

 mals. _ Among these, however, favorable opportunities for sys- 

 tematic treatment along the lines suggested would rarely be 

 offered while,^ on the other hand, the successful treatment of 

 an occasional individual bears no comparison with the beautiful 

 results that are obtained by prophylactic measures in the sup- 

 p^-ession of the disease. Nevertheless the proper regulation 

 of hygienic conditions in infected herds, and especially the 

 restriction of stable life to the minimum, as well as cleanliness 

 in stables where these are a necessity, are of immense im- 

 portance in the solution of the problem of the suppression of 

 tuberculosis. 



The systematic treatment with tuberculin, in spite of the 



