THE MORE COMMON AILMENTS OF CATTLE 437 



It occurs most frequently with cattle and sheep. It may 

 also occur in the human family. It is caused by a micro- 

 scopic organism known as the anthrax bacillus, which is 

 a minute rod-shaped germ that may be found in the 

 blood and tissues of affected animals. These germs are 

 susceptible of rapid and endless multiplication. Death 

 follows as a result of the extent to which they introduce 

 poisonous substances into the system. In the spore 

 stage the germs live outside of the body and may retain 

 their virulent properties for years in the dried form, and 

 their power to resist heat is such that water must boil 

 in order to destroy them. On the other hand, outbreaks 

 may occur in the cold weather of winter. 



Anthrax germs may be conveyed in many ways, as 

 (i) through imported hides, hair, and wool; (2) through 

 fertilizing materials made from animals infected by the 

 disease; (3) by running water coming from tanneries or 

 areas previously infected ; (4) by the bite and feet of 

 insects that have come in touch with the virus; (5) by 

 the feet of dogs and birds that have been feeding on the 

 carrion; and (6) through food materials from infected 

 lands. It sometimes reaches the human family through 

 the handling of materials, as wool from animals that 

 have been affected with the disease. Certain conditions, 

 as heat and moisture, favor the spread of the disease, and 

 this is also influenced by soil conditions. The disease 

 thrives best in moist areas, in mild and warm climates, 

 and in black humus and peaty soils. 



Anthrax may reach its victims, first, through res- 

 piration ; second, through the skin ; and, third, through 

 the digestive tract. By the first of these methods, the 

 disease reaches chiefly the individuals of the human 

 family, as those engaged in sorting infected wool ; by 

 the second, it more frequently reaches the less thick- 

 skinned animals, as the horse and the mule, the virus 

 being carried to a considerable extent by insects; by the 

 third, it usually reaches cattle in their food and drink, 



