ULAN DEBS— MALLEUS 423 



nodular thickening or ulcer formation on any part of the 

 body, especially under the abdomen, sheath or udder should 

 be looked upon with suspicion. 



Differential Diagnosis. — There are a number of diseases 

 producing nasal discharge, lesions on the nasal mucous 

 membranes, swellings of the submaxillary lymph glands, 

 and nodules and ulcers in the skin. At times some of these 

 appear strikingly like glanders. Formerly when a differen- 

 tiation was only possible by carefully weighing the clinical 

 phenomena these diseases were extremely important to 

 consider. However, we have now available several accurate 

 methods of diagnosis which can be employed. When doubt 

 exists in clinical cases or when there is no clinical evidence of 

 the disease, although the patient has been exposed, the 

 following methods of diagnosis are now available. 



(a) The Mallein Test.— Mallein which is prepared from 

 the glanders bacillus, much as tuberculin is prepared from the 

 tubercle bacillus, when properly used, is a reliable test for 

 glanders. It may be instilled into the eyelid (ophthalmic 

 reaction) or applied subcutaneously (hypodermic) or rubbed 

 into a disinfected area of the scarified skin (endermic). The 

 ophthalmic method is now most generally employed and 

 seems to be the most accurate of the three. 



The ophthalmic method of using mallein* is quite simple. 

 It consists in dropping into one of the eyes of the animal to 

 be tested 3 to 5 drops of concentrated mallein, or the mallein 

 may be introduced into the conjunctival sac with a camel- 

 hair brush. The reaction usually begins five or six hours 

 after the instillation of the mallein and lasts from twenty-four 

 to thirty-six hours. A positive reaction is manifested by an 

 accumulation of yellow exudate at the inner canthus of the 

 eye to which the mallein has been applied. In some cases 

 the discharge is very slight, in others profuse and usually 

 associated with severe conjunctivitis; at other times the 

 conjunctivitis is absent. The intensity of the reaction is not 

 an index of the extent of the disease. Ordinary mallein 

 used for subcutaneous testing is not adaptable. The Bureau 

 of Animal Industry prepares a special mallein for ophthalmic 

 tests, which contains no glycerin as a preservative. Some 



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