156 - THEORY AND PRACTICE 



anthrax is due to inoculation through a wound, it is called malig- 

 nant pustide. 



Anthrax is essentially malignant. As a rule it develops 

 without any swellings or external manifestations, although there 

 may be swelling. All warm blooded animals are subject to it. 

 At one time it was thought that the birds and fowls did not have 

 it, but this is erroneous. The disease usually runs a rapid fatal 

 course, sometimes killing in 12-24 hours. In the horse manv 

 mild cases recover, but the recovery is slow. Some never fully 

 get over the disease. A notable case of anthrax among fast 

 horses, pacers and trotters was related by Dr. Baker. They may 

 recover, but they never recover their former usefulness. They 

 may have a wabbly gait. 



Anthrax has been known from time immemorial. In the 

 siege of Troy, animals are recorded as having died of anthrax. 

 The people ate the animals and 60,000 of them died. It occurs 

 epizootically and enzootically. 



Etiology. — The cause of anthrax is the bacillus anthracis. It 

 was discovered by two Frenchmen in 1850 — Rayer and Davaine. 

 The disease is communicable from animal to animal and from 

 animal to people. The germs may be taken in through any 

 channel, but most often by the mouth through food. The germs 

 can enter any abraided surface, wounded skin, etc. In case of a 

 skin wound the part should be excised. People can get malig- 

 nant pustule through handling dirty rags, etc. Whether the 

 animal dies from the disease or not depends upon the conditions 

 of immunity. The course of the disease depends upon: 



1. The natural immunity of the animal. 



2. Strength of the culture, that is the 



amount of attenuation of the germs. 



3. Number of germs inoculated. 



The period of incubation is short — may be four hours. The 

 disease is non-recurrent. One attack renders immunity to an 

 animal. Pasteur proved this to be true and because of his in- 

 vestigations we now practice vaccination against it. He used 

 broth as a culture medium and kept it at a temperature of 42 

 degrees C. He found tnat the germs died in a month. When he 

 introduced the broth into a healthy animal, it produced a consti- 



