466 INFLAMMATIONS. 



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 

 that it is caused by an insect of the acarus tribe, which has been 

 detected by the microscope in many cases, but which by some 

 people is maintained to be an accidental effect, and not a cause of 

 mange. However this may be, it is found that remedies which 

 are destructive to insect life, are by far the most efficacious, such 

 as hellebore, sulphur, corrosive sublimate, tobacco, &c. The second 

 kind of virulent mange is more rare than that described above, 

 and still more difficult of cure, the vegetable parasite being less 

 easily destroyed than the insect. This parasite is supposed to be 

 of the nature of mould or fungus, which we all know is most ob- 

 stinately tenacious of life, and is reproduced again and again in 

 any liquid where it has once developed its germs. In outward 

 appearance this variety of mange differs very little from the insect- 



