276 TUBERCULOSIS. 
and bring them up on the milk of the healthy herd alone. The 
healthy herd must be tested every six months or so, and if any 
show reaction they must at once be removed from the rest. The 
tuberculous herd may be kept and milked, but the milk should be 
sterilized. By keeping up this procedure for a few years, it is possible 
to eliminate the infected animals and have left a herd of healthy 
animals. 
4. A still more recent plan has been widely adopted in Germany 
and seems at present to offer the simplest and most hopeful solution. 
It consists in separating all calves, as soon as born, from their 
mothers, and rearing them separately from the rest of the herd. 
Tuberculosis is not hereditary, and the calves of tuberculous mothers 
are, when born, free from the disease (except in rare instances). 
If, therefore, they are at once separated from their mothers, brought 
up on pasteurized milk, and not allowed any possible contact with 
the other animals, they may be reared free from the disease, becoming 
in a few years a herd of healthy cattle, and if they are guarded from 
outside sources of contamination they will continue to be free from 
the disease. Meantime the animals in the infected herd, whose 
milk may be used if throughly pasteurized, may be slowly disposed of, 
while the healthy, growing herd gradually replaces them with the 
smallest possible loss to their owner. Of course the healthy 
animals must not be allowed to enter the quarters formerly occupied 
by the diseased herd until there has been a thorough disinfection 
of the premises. 
Which of these methods of procedure it is best to adopt depends 
upon circumstances. If a man has only a small number of animals 
and only one or two of them are tuberculous, his simplest plan 
will be to slaughter the reacting animals at once. If his herd is a 
large one, it is best to build up a healthy herd by one of the methods 
outlined. He must remember that a single tuberculous animal 
is a menace to his entire herd and he should begin his fight against 
the disease at the very first discovery of an affected animal. Neglect 
in using the tuberculin for fear that some reacting animals be found 
in the herd is the height of folly. Half-way measures in handling 
this subject are no better than none. 
