24 VETERINARY PARASITOLOGY 
is frequently attacked, and becomes denuded of hair. 
It assumes the same dark slaty-grey colour as in the 
pustular type, and is hot to the touch. Itching is very 
slight. The surface of the skin is dry and covered with 
desquamated epithelial scales. The absence of pustules 
is probably due to the fact that the parasites in this type 
of case are few in number in each sebaceous gland, and 
the inflammation set up is not sufficiently intense to 
cause pouring out of exudate and escape of leucocytes, 
and so pustules are not produced. In both types of 
the disease the animals appear wretched, become very 
emaciated, and often die. 
In the cat the eruption is similar, but it is more 
frequently confined to the head. 
Symploms in Other Animals—In cattle the skin 
covering the whole body may be affected. The erup- 
tion takes the form of pustules about the size of a pea, 
but it is stated that cattle spontaneously recover from 
the disease. 
In pigs the Demodex is much broader than the 
Demodex jolliculorum of dogs, and the pustules they 
give rise to show a great tendency to become confluent, 
and so large swellings are produced. They attack the 
head, snout, and lower surface of the body. 
Prognvsis.—This must be considered unfavourable, 
especially if the disease has been existent for any length 
of time. It is usually the case that, when one portion 
of the skin is apparently cured, the disease breaks out 
again in some other part, and although months may be 
spent in treatment, little benefit may result. 
Treatment.— Among the commonest agents employed 
are the following: Sulphur, tar, iodine, potassium sul- 
phurata, zinc chloride, Peruvian balsam, ung. can- 
tharides, sublimate ointment, creolin, etc. 
i. In early stages, when the patches are few in 
number and of small extent, it has been thought ad- 
