DISEASES OF THE BLOOD. 145 



diseased cow given to pigs generated the disease. Thus, 

 it seems that the virus may gain entry into the system 

 through almost any mucous membrane. Nature endeavours 

 to throw off the contagium after it has entered into the 

 blood through the mucous membranes and such parts of 

 the skin as we have indicated as being involved. Inocu- 

 lations at first failed, but Contamine produced the disease 

 by inoculation of the mouth, and since then this process 

 has been resorted to, not with a view to prevent recurrence, 

 but in order to ensure all animals of a herd being simul- 

 taneously affected, whereby the period of isolation, as en- 

 forced by law, is shortened. This inoculation is a measure 

 of questionable value, since some animals might have 

 escaped by proper segregation and disinfection, and also 

 the same animal may be several times affected. The virus 

 may be conveyed by attendants or by appliances ; also it is 

 said to be carried for a distance of 120 yards, but this pro- 

 bably depends upon the direction of prevailing winds and 

 other atmospheric influences. The virus is said to retain 

 its vitality for at least three months. 



Diagnosis. — Eczema epizootica may be confounded with 

 aphtha simplex, and undoubtedly has been by some 

 authors. The latter appears under an enzootic form, 

 dependent upon special characters of the food. The 

 lesions are confined to the mouth, and consist of very 

 numerous true vesicas, surrounded by an areola or ring 

 of redness, due to inflammation, and pointed. These 

 contrast markedly with the large blebs of eczema epi- 

 zootica, which are few in number, and occur in definite 

 positions. A difficulty is presented to inspectors in the 

 later stages of this disorder in determining whether foot 

 lesions are specific or simply due to the disease called foul. 

 Complicated foot lesions succeeding eczema are really one 

 form of foul. All chronic cases of this kind may be 

 passed as incapable of communicating the disease. The 

 same remark applies to glossitis and disease of the 

 mammary gland. 



Treatment, as in other eruptive disorders, must be 

 directed to avoidance of complications and assistance of 



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