No. 6. DEPARTMENT OF AGRICULTURE. 129 



Numerous instances of exceedinj^ly lieuvy losses arising from the 

 prevalence of tuberculosis in lieids could be cited. Two may be 

 taken to serve as an illustration of many. A pure-bred herd that 

 had been built up with much expense and effort, extending over 

 twenty years, became infected with tuberculosis. Infection was 

 shown first by loss of condition of a few of the older cows. These 

 cows gradually became thin, and coughed more or less, ^^'hen they 

 fell into such a condition that they could no longer be used as dairy 

 animals they were sold for slaughter. Later, some of the younger 

 animals in the herd became unthrifty; they declined in condition, 

 consumed a great deal of food but did not profit by it and were 

 killed or died. This sort of thing was repeated so often that the 

 owner had his herd examined and this led to the removal of several 

 cows showing signs of advanced tuberculosis. But the trouble 

 did not cease, and so a State inspection and State aid were applied 

 for, with the result that all but one of the herd of about thirty 

 cows were found to be tubercular. These cows were killed and 

 the antemortem diagnosis was proven in each case by the post- 

 mortem examination. The fault here was that the owner of the 

 herd permitted it to remain infected for so long without taking 

 effective measures to discover the infected animals and isolate them 

 from those that were still healthy. If this had been done as soon 

 as there was reason to believe that there was infection in the herd, 

 there can be no doubt that a large number of the members of the 

 herd could have been saved. Many instances have occurred wherein 

 herds have been inspected immediately after the appearance of the 

 first evidence of tuberculosis. Uusually, in such cases, it is found 

 that the distribution of the disease is small. Sometimes, when the 

 inspection is made immediately after the owner has received his 

 first intimation of the. existence of tuberculosis among his cattle, 

 it is found that the disease is even then widespread and involves 

 a large proportion of the members of the herd. Usually, however, 

 in such cases, the disease has been present in the herd for a much 

 longer time than was at first thought by the owner and the earlier 

 manifestations of its presence were disregarded, through lack of 

 knowledge of their significance. 



A recent instance has been observed that instructively illustrates 

 a method by which tuberculosis may enter a herd. A large breed- 

 ing and dairy herd that had been founded for a long time was known, 

 as a result of its having been tested with tuberculin, to be free from 

 tuberculosis. Some young cattle purchased for addition to this 

 herd were tested with tuberculin and found to be sound. After- 

 wards, they were pastured for the entire season on an outlying 

 farm, in contact with tubercular cattle belonging to another herd. 



9—6—1903 



