324 AGRICULTURAL BACTERIOLOGY 



glandered horse, is hot and painful and continues to in- 

 crease in size for from twenty-four to thirty-six hours. The 

 swelling persists for several days, disappearing in from 

 eight to ten days. At the time the swelling is most promi- 

 nent, the diseased animal appears dull, breathes rapidly, 

 and has a poor appetite. In the case of a healthy horse, the 

 swelling is small and disappears in twenty-four hours, and 

 no signs of illness are to be noted following the injection of 

 the mallein. The constitutional reaction in the diseased 

 animal is accompanied by an increase in the temperature 

 ranging from two to two and five tenths degrees. The in- 

 crease begins about eight hours after the injection and 

 reaches the maximum in from ten to fifteen hours. The 

 fever persists for from twenty-four to forty-eight hours, 

 instead of only a few hours, as in the tuberculin test. In 

 the healthy horse there is no appreciable rise in tempera- 

 ture. 



The test is not so accurate a method of diagnosing glan- 

 ders as is tuberculin for tuberculosis, for some glandered 

 horses do not react to the test; but a positive reaction is 

 looked upon as proof of the diseased condition of the animal. 

 Other tests are also employed, in which the blood is exam- 

 ined for certain of the anti-bodies that will be produced 

 under the stimulus of the glanders bacillus. These meth- 

 ods can be carried out only in the laboratory. 



The farmer must seek to protect himself by the purchase 

 of animals from known healthy sources, and by care in pre- 

 venting his animals from coming in contact with infectious 

 material in public places. The organism does not form 

 spores and hence is not especially resistant. 



Tetanus. Tetanus, or lockjaw, is an example of a tox- 

 emia. It is also an example of a disease caused by a micro- 

 organism that is not transmitted from one animal to another 

 under natural conditions. B. tetani is widely distributed 



