FAVUS. B17 
Soon, however, bright yellow specks appear, which rapidly increase in size 
until the peculiar cup-like crusts are developed. 
These, the centre of each of which is generally pierced by a hair, vary in 
size from that of a pea to a shilling; and many of them coalesce or run to- 
gether, and thus large, thick, irregular crusts are formed. 
Single crusts can be easily detached without breaking ; and when removed, 
in every instance a cup-shaped depression is left. 
The crusts emit a peculiar musty odor. If allowed to remain, by continued 
pressure they so affect the hair at its roots that it falls out. Nor does it ever 
grow again with former luxuriance, while the hairs restored are coarse, wiry 
and unmanageable. 
Itching is not a symptom of favus; instead, the eruption is attended with 
pain; but it is not severe. 
The disease is contagious and may be not only transmitted from one dog to 
another, but from dogs to mankind; and it is interesting to note that besides 
dogs it has been observed in mice, rabbits, cats and hens. 
While the real cause of favus is a parasite and fungus growth, and the same 
can be conveyed from one subject to another, as with all like diseases, certain 
general conditions favor it. For instance, it flourishes best upon the skins 
of dogs that are poorly fed and otherwise badly managed, and consequently 
are not in high health. In other words, although contagious this affection 
is much less so than many other affections of the same class; and dogs that 
are frequently groomed and well kept would not likely become diseased, even 
were the spores which produce it conveyed to them, because clean and healthy 
skins are not soil that is favorable to the development and growth of the 
germs. 
Favus is curable, but not without patience and careful treatment. The 
spores of the fungus penetrate to the deepest parts of the hair-follicles, and to 
reach them with applications is always exceedingly difficult, and scarcely pos- 
sible before the hairs in the affected spots have been pulled out. 
The first essential step is to soak the crusts with lard or an oil, and when 
they have been detached, all the hairs in the affected spots should be drawn 
out. If the disease is not extensive, the following may then be applied three 
times daily : 
Sulphuret of potassium, one drachm; green soap, four drachms; lard, one 
and one-half ounce. 
Where the disease is extensive the proportion of the potassa in this prep- 
aration should be reduced to one-half or one-fourth, as appears necessary; or 
in such cases an excellent application would be the following : 
Chrysarobin, twenty-five grains; chloroform, one drachm; flexible collo- 
dion, seven drachms. 
This should be very quickly applied with a camel’s-hair brush, and one 
