290 ACUTE GENERAL INFECTIOUS DISEASES 



Prophylaxis. — When an outbreak occurs all cattle two years 

 old and under should be promptly removed to a preferably 

 higher and drier pasture. In stable-fed victims a change to 

 known uninfected food is imperative. The dead should be 

 disposed of, as recommended under Anthrax. Exposed ani- 

 mals should be vaccinated which successfully protects against 

 serious infection. Black-leg vaccines are now obtainable 

 from many State experiment stations, the Bureau of Animal 

 Industry, and several commercial houses dealing in biological 

 products. 



Application. — The vaccine is administered by injecting it 

 under the skin, the patient being properly secured. Usually 

 the needle is inserted in the thin, loose skin just in front of 

 the shoulder. Previous disinfection is not necessary, but the 

 needle and syringe must be first sterilized. The dose will 

 depend upon the vaccine used. Cattle may be vaccinated 

 any time of the year. Cattle already infected should not be 

 treated; the vaccine has no curative value. Hiefers in ad- 

 vanced pregnancy should not be vaccinated. Revaccination 

 may be practised with safety in two weeks. The immunity 

 conferred reaches full development in eight to ten days, dur- 

 ing which time the patients pass through the negative phase, 

 and are therefore more susceptible to infection than if they 

 had not been vaccinated. The immunity lasts from, twelve 

 to eighteen months. 



BRAXY. GASTROMYCOSIS OVIS. 



Definition. — An infectious disease of sheep characterized by 

 its short, fatal course, and due to a specific anaerobic bacillus 

 resembling the black-leg bacillus. 



Occurrence. — Braxy has not yet been reported in the United 

 States. In Norway, Denmark, Iceland, Germany, and Scot- 

 land it is common, leading to great losses among yearling 

 lambs. The disease is rarely seen in suckling lambs or in 

 sheep over two years of age. While sporadic cases may occur 

 during the summer months when sheep are on pasture, serious 

 outbreaks take place during the late fall and early winter 

 months after the sheep have been returned to the fold for 



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