DISEASES OF THE SKIN AMONG DOMESTICATED ANIMALS. 
33 
The symptoms consist of a vivid arterial reddening of the skin, 
which disappears on pressure. It is, of course, only visible on 
unpigmented spots, and can only be seen in animals under certain 
special conditions. The affected part is almost always evenly in¬ 
jected, a macular eruption, such as is sometimes seen in erythema 
hominis, being extremely rare. 
Itching is rarely present in pure erythema in dogs. As a rale 
the affection disappears without leaving any trace, as soon as the 
cause is removed. Only when the hyperaemia has been very in¬ 
tense is there subsequent desquamation of the cuticle; or a pig¬ 
mented spot is left behind, which slowly fades away. 
The treatment of erythema is to be commenced with the re¬ 
moval of the cause. Then leadwater, or carbolized lotions, and 
ointments of zinc oxide or salicylic acid may be used. Finally, 
when there is much itching, solutions of nitrate of silver may be 
employed. 
2.—Dermatitis Erythematosa. 
This is distinguished from erythema simplex in that the 
stratum mucosurn is swollen from exudation and cell emigration, 
and that sometimes the stratum eorneum is raised and serous ves¬ 
icles are formed, which may be ruptured. 
D. erythematosa merges into eczema, and is seen especially in 
the sheep in the form of buehweizenausschlages, (fagopyrismus). 
This is seen when sheep are fed with the various kinds of poly- 
gonacese, especially polygonum fagopyrum, and are subsequently 
exposed to the action of the solar rays. Many explanations of 
this peculiar action have been given. The most probable one is 
that the use of this variety of food causes increased circulatory 
activity, and then the heat of the sun causes a kind of “ erythema 
solare.” 
On the other hand it has been claimed that it is not the poly- 
gonacese as such which causes the eruption, but parasitic fungi of 
this species of food which come in contact with the skin of the an¬ 
imals, and cause the eruptions—especially where the increased 
solar heat renders its development rapid. 
We have not space to discuss the arguments for and against 
these theories. 
