DIPHTHEBIA AND GLANDBES GEOUP 389 



affected, the disease is termed farcy. The disease may be 

 either acute or chronic. The former is more common in the 

 ass and mule, the latter in the horse. The chronic type of 

 disease may not show anything particularly characteristic 

 in the early stages, but the lymph nodes become enlarged. 

 The lesions are generally present on the nasal mucosa in the 

 lungs and in the lymph glands. When these occur in the 

 nose they break down, form pus and develop into chronic 

 ulcers which eventually heal with the formation of a star- 

 shaped scar which is quite characteristic. In farcy or 

 cutaneous glanders nodules form below the skin, the lymph 

 glands and ducts become swollen and appear like strings of 

 beads. When these nodules become enlarged they may 

 break through to the surface of the skin and ulcerate. In 

 man the organism commonly gains entrance through a 

 wound in the skin or by inhalation and is generally fatal. 



Immunity. — Practicable methods of either active or pas- 

 sive immunization against glanders have not been devel- 

 oped, although many attempts have been made. 



Diagnosis. — The disease glanders is particularly dan- 

 gerous not only because of the high mortality among horses 

 affected, but also because of its transmissibility to man. In 

 most states in the United States animals known to have 

 glanders must be killed and the body completely destroyed 

 by burning. Inasmuch as the disease is difficult to recog- 

 nize clinically in chronic cases, several methods of diagnosis 

 have been worked out for this disease. It is possible to use 

 the agglutination test. In general horse serum will not 

 agglutinate 'glanders bacilli in dilutions of one to four 

 hundred or more unless the animal is diseased. Usually 

 diseased animals will show agglutination in dilutions of 

 serum of one to two thousand. Fixation of complement has 

 also been used as a satisfactory method of diagnosis of the 

 disease. Most commonly used, however, is the so-called 

 mallein test. Mallein is prepared by growing the organism 



