320 KENNEL DISEASES. 
PSORIASIS. 
Psoriasis is a chronic disease, which usually begins as small red pimples 
scarcely larger than pin-heads, each being surmounted by a thin scale. These 
may be abundant and well scattered, and show but little if any tendency to 
increase in size; but as a rule they spread, and some of the patches coalesce or 
unite, and thus the eruption has the appearance of mortar spattered over the 
skin. 
In some cases the patches are few but of considerable size, and by uniting 
they cover large areas. 
As each patch spreads, its centre cleans up, and the skin at that point 
becomes normal; consequently after a time the eruption is really a series of 
ridges of red and thickened skin, covered with dry white glistening scales that 
have been termed mother-of-pearl-like; and these ridges, although irregular, 
all approach ring-like forms. 
This disease itches as it makes its appearance, but that disturbance is only 
slight. 
As to causation, practically nothing is known; the affection exhibiting little 
or no partiality in choosing its victims. 
The most convenient application for this affection consists largely of col- 
lodion, because remedies incorporated with that are fastened, as it were, to the 
eruption. It is composed as follows : 
Chrysarobin, twenty-five grains; salicylic acid, twenty-five grains ; chloro- 
form, one drachm; flexible collodion, seven drachms. 
This should be quickly applied, with a small, stiff paint-brush, once’ daily ; 
and its use be persisted in until the skin is nearly restored to normal condition. 
It can safely be assumed that whenever the vitality is impaired the occur- 
rence of this affection is favored, therefore if the general health of the patient 
is not good, appropriate treatment ought to be administered to restore it. 
