424 CHRONIC INFECTIOUS. DISEASES 



experimenters have used dry mallein (fnallein siccum). As a 

 rule positive reactions are not attended by fever or systemic 

 disturbances. Some glandered horses, however, are so 

 hypersensitive to mallein that they give a thermic reaction. 

 It is therefore advisable to take the temperature just before 

 the mallein is instilled and again when the eye is being 

 examined to determine the reaction. When the reaction is 

 doubtful the complement-fixation test may be used as a 

 control. The test may be repeated within twenty-four hours 

 on the same or control eye. If another retest is necessary 

 it should not be made in less than three weeks. 

 The subcutaneous method is applied as follows: 



1. The normal rectal temperatures of the horse to be 

 tested are first determined one or two days before the injec- 

 tion of mallein is made, best taking them each morning, 

 noon, and evening. 



2. The mallein is injected in doses of 1 c.c. into the side 

 of the neck. 



3. Beginning four to eight hours after the injection, the 

 postinjection temperatures are obtained every two hours 

 until the twentieth hour after injection, and carefully 

 recorded. 



Interpretation of Results. — A typical reaction consists in 

 an elevation of temperature of at least 3.6° F., and must 

 exceed 104° F. The temperature curve usually remains at an 

 elevation for some time, or it may take a slight drop and 

 rise again later in the day. Such a reaction is spoken of as 

 positive. On the second and sometimes on the third day 

 a second temperature curve, though usually less pronounced, 

 may occur. 



When the postinjection temperature exceeds the highest 

 preinjection temperature 2.7° F. and reaches 103.1° F. 

 or over, and a marked swelling occurs at the point of 

 inoculation, the swelling being hot, sensitive and at least 

 5 to, 10 cm. in diameter the reaction is positive. The swelling 

 should persist for at least twenty-four to thirty hours. 



The reaction is doubtful even if the temperature exceeds 

 3.6° F. and no local reaction appears. 



The reaction is negative when, notwithstanding the height 



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