636 GENERAL THERAPEUTIC MEASURES 



anthrax serum on, one Side of the animal, and the injection of an attenu- 

 ated spore vaccine on the other side. The advantages of this method are 

 apparent. It confers immediate protection, requires only a single han- 

 dling and reduces the losses from vaccination to a minimum. 



These investigations have further established that should it be found 

 desirable to employ the double vaccination, it is much safer to use attenu- 

 ated spore vaccines than the Pasteur vaccines, on account of the better 

 keeping qualities of the product and the possibility of more accurate 

 dosage. These findings were obtained through extensive investigations 

 made by the Bureau of Animal Industry, not only in the laboratories 

 and experiment stations but also in numerous field tests. 



The remarkable curative properties of anti-anthrax serum in the 

 treatment of animals in anthrax infected districts are well established. 

 Since it has been made available for the treatment of this disease, numer- 

 ous reports are at hand which indicate that even in the most severe cases 

 of infection, an intravenous injection of 50 to 100 mils of anti-anthrax 

 serum has often resulted in the recoveries of animals in 1 to 4 days. 

 Veterinarians in anthrax districts should not hesitate to use these new 

 methods of vaccination as they cannot be considered in the experimental 

 stage. The results obtained in hundreds of thousands of animals have 

 demonstrated, and the experiments made by the Department of Agricul- 

 ture should prove sufficient factors for establishing their merits. 



BLACKLEG. 

 (Symptomatic Anthrax.) 



This is a non-contagious, infectious disease of young cattle charac- 

 terized by bloody swelling under the skin on the fleshy parts of the body. 

 The disease is confined almost entirely to young cattle and other species 

 of animals are rarely affected. It is seen most frequently in animals 

 ranging in age from six months to 21^ years, and well-bred, well condi- 

 tioned animals seem more susceptible than scrub stock. 



Cause. 



Blackleg is caused by the Bacillus gangr8ena^ emphysematosae, com- 

 monly known as the "blackleg bacillus." This organism produces spores, 

 or, resistant forms that, once established in the soil, remain for long 

 periods, sometimes several years, until they gain entrance to the animal 

 body, whereupon they grow and reproduce the disease. When this fact 

 is understood the persistence of the disease in a locality is readily compre- 

 hended. Blackleg i^ a pasture disease, the infective agent being found 

 in the soil, and the germs are taken in with the food and water or through 

 slight wounds in the skin, such as briar pricks or barbed wire scratches. 



Treatment. 



Treatment is ineffectual after the disease is once fully developed as 

 it results almost invariably in death. Some have advocated cutting into 

 the swellings, roweling and dragging the animals about. Such measures 

 cannot be too strongly condemned. The fluids which are liberated con- 

 tain the germs of the disease and as a result more infection is distributed 

 to the grief of the owner and loss of future generations of calves. 



More recently the administration of anti blackleg serum has resulted 



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