28o Veterinary Medicine. 



1 : 1 500. The dilution is mixed in equal proportions with the 

 pure blood serum of the suspected animal and placed in an in- 

 cubator at 37° C, for 24 to 30 hours. By this time the serum 

 of a glandered horse will have caused agglutination of the 

 Bacillus mallei and the precipitation of the opaque bodies, leaving 

 the supernatant liquid clear and translucent. The blood-serum 

 of a healthy horse has no such effect, the liquid retaining its 

 opacity throughout. The test is not always available to the 

 average practitioner, as it requires laboratory apparatus and 

 facilities, but, when the means are at hand, it may be employed 

 to confirm the results of the mallein test, or independently in 

 cases attended with marked fever and thereby ill adapted to the 

 mallein test. 



Pathological Anatomy. The colonization of the bacillus mallei 

 in a tissue usually determines a concentration and multiplication 

 of leucocytes, so as to form rounded nests of small lymphoid cells 

 in a scanty fibrous network. These may be miliary or by aggre- 

 gation they form masses the size of a pea or larger, which bear a 

 close resemblance to the neoplasms of tuberculosis. As in tuber- 

 cle the central cells of the group, degenerate, forming a granular 

 fatty debris, and constituting an ulcer or abscess. In certain 

 cases with a proliferation of fibrous tissue a cicatricial material is 

 developed. Another characteristic lesion is the occurrence of 

 hyperplasia in the walls of the lymph vessels so as to constitute 

 firm tender cords, and the infiltration^ of the adjacent lymphatic 

 plexus. 



In the nasal mucosa the bacilli form prolific colonies at different 

 points of the membrane and submucosa with the active production 

 of lymphoid cells, followed by granular fatty degeneration and 

 ulceration: Hence may be found different lesions representing 

 the different stages. First there may be miliary deposits with 

 clear contents and standing out like grains of sand. Then there 

 are the larger pea.-like nodules with congested vessels and minute 

 haemorrhages, but made up largely of the nests of lymphoid cells. 

 These may bear on the surface a distinct blood extravasation, or 

 the epithelium may be raised from the cerium layer by a liquid 

 exudation. The more advanced nodules show the centre light 

 colored, grayish or yellowish with a distinct granular degenera- 

 tion of the cells. I^ater still the degeneration involves the super- 

 ficial layers and epithelium and an open ulcer is formed with a 

 strong tendency to extend in depth and width. The formation 



