PREVENTION, SYMPTOMS AND TREATMENT , r 



wounds, and if virus from the affected area is injected into rabbits 

 these animals will succumb to malignant edema but not to black leg. 



Hemorrhagic septicemia also resembles black leg, but the 

 former attacks cattle of all ages and affects the throat, neck and 

 dewlap, while the swellings do not contain gas and are associated 

 with hemorrhages throughout the body. 



Treatment. — Curative treatment is of little service and by the 

 use of incisions an exit for the escape of myriads of bacilli is af- 

 forded. The spores remain virulent in the soil for some years. 

 The dead bodies should be burned or buried six feet deep in quick- 

 lime, and the surfaces contaminated with infection should be thor- 

 oughly disinfected. The burning of pastures in winter will destroy 

 the infection. After a case has occurred removal of the herd to new 

 pastures may hinder the spread of the disease. Prevention is very 

 successfully secured by inoculation of calves from four months to 

 two years with virus attenuated by heat. This is made by pounding 

 up some affected muscle in a mortar with water and straining the 

 pulp through cloth. If dried at 35 ° C. the bacilli remain virulent 

 for two years. Then when desired for use the dried virus is mixed 

 with two parts of water and dried in thin layers on glass for seven 

 hours at 90 to 94 C, when it occurs as a brown powder ; gm. .01 

 is a dose for a calf. Vaccination is usually done after the calf is 

 six months old, but if younger calves are subject to the disease, it 

 may be done at an earlier age and a second vaccination performed 

 in the second year. After the age of six months only one vaccina- 

 tion is required to protect during life. Immunity begins in ten to 

 twelve days after vaccination. 



Vaccination is done by mixing the powder in water in a mortar, 

 filtering it and injecting it with a hypodermic syringe in the side of 

 the neck in front of the shoulder. The vaccine is given away by 

 the Chief of the Bureau of Animal Industry, U. S. Department of 

 Agriculture, Washington D. G, to stock owners, and it and direc- 

 tions for using the same may be procured by writing to this ad- 



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