CHAPTER XVI. 

 THE DISEASES OF CATTLE. 



There are but three diseases among western range 

 cattle which can be considered general : Big jaw (acti- 

 nomycosis), bloating (tympanites) and black-leg. Bloat- 

 ing has been fully considered under the head of poison- 

 ous plants. Big jaw, also called lumpy jaw and wooden 

 tongue, is an infectious disease found generally all over 

 the West. It is a chronic disease and due to the forma- 

 tion and action of a fungus growth. It is not carried 

 from one animal to another by mere contact but must 

 be taken into the system through some abrasion of the 

 skin in the lining of the mouth or decayed teeth. The 

 fungus is found on grasses and the sharp awns of bar- 

 ley and other grains. These work into the membrane of 

 the mouth, the tongue and gums of cattle. 



In certain stages of the disease animals with huge, 

 running sores on their jaws drink from troughs, pools 

 and tanks into which the matter from the sores drops, 

 and it is an easy matter for the fungus which carries 

 the trouble to find its way into the system of a healthy 

 animal. It is not very probable that the disease is 

 often spread by this means. While the tumors may ap- 

 pear on various parts of the animal, it is generally on 

 the lower jaw bones that they are found. The trouble 

 begins with a small swelling which gradually grows 

 until it assumes considerable size, finally breaking out 

 with a running sore which spreads and grows until the 



