268 SPECIFIC DISEASES. 



while being distinctly different to the anthrax bacillus, causes 

 symptoms which simulate those of that disease. It is a very 

 fatal affection, but does not spread so rapidly throughout a flock 

 as anthrax fever. Like anthrax, it generally selects the fattest 

 and best feeders in the flock for its victims. The disease runs a 

 rapid course, and a very small percentage of the affected animals 

 make a recovery. It is due to the introduction in the system of 

 a vegetable micro-organism, which in size is slightly larger than 

 the bacillus anthracis. It appears to localize itself in certain 

 parts of the system, being present in the effusion of the affected 

 quarter, but is absent in the spleen. Its methods of infection are 

 very similar to those of anthrax. Low-lying pastures and 

 grounds bordering on streams seem to be fertile localities for 

 harboring the germs. The soil on which black-leg patients have 

 died abounds with the bacilli, the grass on these spots generally 

 growing very rank from the fertilizing effect of the carcass, and 

 is eaten by the best feeders of the flock, which are not so par- 

 ticular about their diet as those which do not feed so heartily, 

 the consequence being that they become inoculated with the 

 germs of the disease, which develop with fatal effect. This in 

 part accounts for the fact that the fattest animals generally are 

 the first to be attacked, their plethoric condition also favoring 

 the rapid multiplication of the germs. It is a common dis- 

 ease of both cattle and sheep, generaly seeming to prefer the 

 young, immature members of the herd or flock, but older animals 



are not immune. 



Symptoms. 



The sheep is noticed to be dull, off its feed, found lying 

 down. If the disease has not progressd so far as to prevent the 

 animal from getting up, it will be slow in its movements and 

 very lame, either in front or behind, depending as to whether 

 the fore or hind quarters are attacked. If the animal is down 

 and unable to rise, an examination will reveal swelling of a fore 



