154 



COMMON DISEASES. 



necessarily lose in tissue nutrition and vitality, and gradually be- 

 come absorbed or diseased. It is reasonable to expect such lungs 

 to become tuberculous, for cattle and people alike have frequent 

 opportunities for infection. We must realize that nature's laws 

 cannot be violated without paying an inevitable penalty. 



It is unwise to buy cattle for breeding purposes without 

 knowing that they are free from tuberculosis before placing with 

 the herd. All sires, and it is especially true of cattle, should have 

 abundant exercise in open yards or on tread mills, or be driven 

 or worked. Ventilation must be thorough and barns should be 

 constructed with a view to allowing the entrance of unlimited 

 sunshine. Sunshine may spoil the luster of hair, but it also kills 

 germs. 



FIG. 60. BOVINE TUBERCULOSIS. (M. II. li.) 

 TubtTcli s on the great mesentery. 



Summary. — Do not found a herd with tuberculous stock. Do 

 not introduce the disease while trying to improve a herd. Do 

 not allow suspicious animals to stand in stable with healthy ones. 

 Avoid incautious breeding, and close confinement. Ventilate 

 freely. Allow plenty of fresh air, exercise and sunshine especially 

 to breeding stock. 



