318 INFECTIOUS DISEASES 



amination of a piece of the tumor, or some of the pus, may be 

 necessary. 



The treatment is surgical and medicinal. Small, external 

 tumors may be removed by an operation. Sometimes an incision 

 is made into the diseased tissue and a caustic preparation intro- 

 duced. 



The most desirable method of treatment is the administration 

 of large doses of iodide of potassium in a drench, or in the 

 drinking water. The dose is from one to three drachms daily 

 for a period of seven to fourteen days. The size of the dose 

 depends on the size of the animal and its susceptibility to iodism. 

 An animal weighing 1000 pounds may be given two drachms. 

 The treatment is kept up until the symptoms of iodism develop. 

 The condition is indicated by a loss of appetite and a catarrhal 

 discharge from the eyes and nostrils. \Vhen this occurs, the 

 treatment should be stopped, and the animal drenched with one- 

 half pound of Epsom salts, and the dose repeated after three 

 or four days. After an interval of tw^o weeks, the iodide of 

 potassium treatment should be repeated if the growth of the 

 tumor is not checked. 



Emphysematous Anthrax, " Black Leg." — " Black leg " 

 is an acute infectious disease of cattle that is characterized by 

 lameness and superficial swellings in the region of the shoulder, 

 quarter or neck. The swellings are hot and painful and usually 

 contain gas. 



The specific cause of " black leg " is a rod-shaped, spore- 

 producing germ, the bacillus of emphysematous anthrax (Fig. 

 110). This germ possesses great vitality, and may live indefi- 

 nitely in the soil. It has been known to live for years in clay and 

 undrained soils. Young animals that are in high condition are 

 predisposed to the disease. 



The germ enters the body through abrasions in the skin and 

 mucous membrane of the mouth and intestines. 



" Black leg " is a common disease of young cattle in all 



