Bureau of Agricultuee. _ 345 



animal has been kicked or has fallen, but when the swell- 

 ing is closely examined by passing the hand over it, a 

 sound peculiar to the disease is heard, as if the skin had 

 been blown up with air. The black leg bacillus is an air 

 producing germ, and when the swelling is excised, the 

 exudate is a foamy, black fluid with an odor very similar 

 to rancid butter; the muscular tissue underneath this 

 swelling is of a very dark color; hence the name Black 

 Leg. The swelling at first is hot and painful, later be- 

 coming cold and stiff with the skin assuming a parch- 

 ment-like condition, so that the animal finally does not 

 evince pain upon pressure. The rapid course and the de- 

 velopment of the characteristic crepitant swelling makes 

 the diagnosis fairly easy. The disease very seldom, if 

 ever, is found to exist among animals that are continu- 

 ously stabled. Treatment of animals affected with black 

 leg is seldom ever attempted, because it has been shown 

 that the percentage of recoveries does not in any way 

 justify it. The safest method of procedure in herds, in 

 which the disease exists, is to slaughter diseased animals 

 and to vaccinate all susceptible exposed animals. Vac- 

 cination consists of injecting subcutaneously attenuated 

 virus, which will confer an immunity lasting as a rule 

 long enough to protect the animal until it is old enough 

 to acquire a natural immunity. To successfully control 

 outbreaks of this disease I wish to call particular atten- 

 tion to the disposition of the carcasses. Animals dying 

 from black leg should not be removed from the point 

 where they are found. If it actually becomes necessary 

 that such carcass be removed, do not drag it over the 

 ground, as the fluids discharged will infect the soil, 

 and the danger of future outbreaks increased. All car- 

 casses should be completely burned, and not buried in a 

 shallow grave, as is customary. No carcass should be 

 left lying on the ground where dogs, cats, birds or ver- 

 min might visit, as any of the above might carry the in- 

 fection to clean pastures or herds. The removal of the 

 hides of these carcasses should not be permitted under 

 any circumstances. The disinfection of the ground by 

 the free use of lime and a strong disinfectant solution is 

 necessary. Comparatively few counties in the state have 

 escaped outbreaks of black leg in the last year, but the 



