TUBERCULOSIS. 427 



The reaction from the intradermic test consists of a swelling at 

 the point of injection and is observed from 72 to 150 hours after 

 the injection. The character of the swelling varies, and a proper 

 diagnosis of tuberculosis by this test can be made only by an ex- 

 perienced person. 



THE OPHTHALMIC TEST (INTO THE EYE). 



Still another method, known as the ophthalmic test, is used quite 

 frequently and has been found to be of considerable value in what is 

 known as "check" testing; that is, it is used in connection with 

 either of the previously described methods. Sometimes a tubercu- 

 lous animal that fails to react to those tests shows evidence of the 

 disease upon the application of the ophthalmic test. The ophthal- 

 mic tuberculin is placed in one eye and the other eye is used as a 

 check. A reaction is indicated by a characteristic discharge from 

 the eye receiving the treatment, which may occur in from 3 to 10 

 hours after the application or even later. Some swelling and inflam- 

 mation of the eye and lids are often noted. 



TREATMENT OF TUBERCULOSIS. 



Treatment of the disease is not seriously considered by any author- 

 ities at the present time. 



The measures to be adopted to prevent the spreading of the disease 

 must take into consideration not only the tubercle bacillus, but like- 

 wise all those circumstances that make cattle more susceptible to the 

 disease, and which have already been dwelt upon. It would be useless 

 to repeat here all that has been said above on the transmission of 

 tubercle bacilli from one animal to another, and on the dangers of 

 certain debilitating influences. A careful study of these influences 

 will show how tuberculosis may, at least in some cases, be pre- 

 vented. Great care should be bestowed upon the breeding, the sur- 

 roundings, and the feed of the animal, so that the latter may be put 

 into a condition to resist infection even when exposed to it. A tuber- 

 culin teet should be applied to all strange cattle before they are 

 introduced into the herd, and those which show a reaction should 

 be refused. 



A rigid exclusion of tuberculous animals is all that is necessary to 

 prevent the appearance of the disease, provided cattle are not infected 

 by consumptive persons and animals. The transmission of the dis- 

 ease from man to cattle is probably not frequent, but is regarded 

 as a possible source of infection. 



Tuberculosis in cattle must also be considered as bearing upon 

 tuberculosis of other domesticated animals, particularly hogs. In 

 Europe and the United States this disease is not uncommon among 

 hogs, and appears to be on the increase. The reason for its existence 

 may be looked for in the feeding of pigs with skim milk, buttermilk, 

 and whey from creameries, with the offal of the abattoirs, with the 

 household refuse generally, and behind tuberculous cattle. If tuber- 



