VIRULENT ^lAXGE. 419 



health. The arsenic must be administered for weeks or even 

 months, and as soon as the itching seems abating, and the health 

 is improved, the mangy parts of the skin may be slightly dressed 

 with small quantities of sulphur and pitch ointments mixed in 

 equal proportions. By a perseverance in these remedies for two 

 or three months, the blood becomes purified, and the eruption dis- 

 appears, after which, if the health seems impaired, a stomachic or 

 tonic, (59) or (62), will often be required. Sometimes the oint- 

 ment (58a) will be required. 



Virulent mange (which may be compared to psora and porrigo in 

 the human subject) is of two kinds, one attributable to a parasitic 

 insect, and the other of vegetable origin. In the former case, 

 which is its most common form, it appears in large kennels where 

 cleanliness is not sufficiently attended to, and when the floors 

 become loaded with the excretions. There is no doubt that this is 

 highly contagious, but there is also little difference of opinion as 

 to its being capable of being bred or developed among a lot of 

 previously healthy dogs if mismanaged in the above way. The 

 skin shows itself bare of hair in large patches of irregular form, 

 and the hair being as it were gradually worn away at the edges, 

 as if by scratching. The skin is dry and rough, with cracks and 

 creases in various directions, from some of which a thin ichorous 

 discharge may be seen to flow, on removing the scabs which fill 

 them. The dog feeds well, but from want of sleep is languid and 

 listless ; there is considerable thirst and some slight feverishness, 

 but very often the flesh is maintained for months at a high rate. 

 The treatment of this form of mange is founded upon the belief 



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