440 THE MANAGEMENT AND FEEDING OF CATTLE 



in the two-year form and even older. It seldom attacks 

 calves under six months. Cattle that are fleshy and fat 

 fall an easier prey to it than those that are lean. In 

 some countries it would appear to be most virulent in 

 low-lying lands, but that is not true of it in the United 

 States, where soil conditions do not seem to affect it, 

 nor does it seem to be influenced by altitude. 



Although the germ may reach cattle through the 

 medium of food or drink, it is now thought that cattle 

 contract the disease by inoculation, either through the 

 skin or mucous membranes, more commonly the former. 

 Punctures of the skin may be caused by such mediun.s 

 as the barbs of wire fences, thorns and the spines on 

 certain plants. Where the germs are numerous, many 

 animals are liable to be infected. 



The indications of blackleg are general, or constitu- 

 tional, and local, and, in nearly all instances, the local 

 symptoms may not be apparent. Prominent among the 

 general symptoms are dullness and great debility, ac- 

 companied by a highly fevered condition. The tem- 

 perature may rise to 107° F. The local symptoms are 

 manifested in swellings or tumors under the skin, which 

 appear within a few hours of the general symptoms. 

 The stricken animal is usually found lying apart by 

 itself. When roused, it manifests stiffness or lameness 

 in one limb, and sometimes in one side of the body. 

 More commonly the tumors referred to will be found 

 on the hind or forequarter, but they may occur on other 

 parts of the body, as the neck, breast, or flanks. They 

 never occur below the knee or hock. When the hand is 

 pressed over the tumor, a peculiar crackling sound is 

 heard, which is caused by the presence of gas in the 

 same. This fact may serve to distinguish the disease 

 from anthrax, but not always from oedema. The latter, 

 however, usually follows abrasions and wounds of some 

 magnitude. In from one to three days, the animals die. 



