166 DISEASES OF THE HOG. 
CHAPTER XVIII. 
ERYSIPELAS. 
This is a constitutional disease characterized by 
inflammation of the skin with fever. 
Causes: Some animals have a predisposition to 
this disease and it only needs some exciting cause 
to develop it. It is usually caused by a wound of 
some kind by which the poison enters the tissue. 
There is a difference of opinion as to what this poi- 
son consists of, but there is no doubt but that it is 
an organism as it has been found, still the results 
of experiments are very conflicting. It also makes 
its appearance without any wound being found on — 
the body and is supposed to be the result of some 
undue excitement of the skin as from the direct 
heat of the sun or exposure to severe cold. It has 
also been ascribed to the kind of food the animal 
has been fed upon, to a deranged condition of the 
digestive organs and to rheumatism. LErysipelas 
has been caused in the human being by stings or 
bites from insects and the scratch of a pin has pro- 
duced it, and no doubt but some of the cases of it 
which we find in pigs are the results of such slight 
injuries. 
