302 KENNEL DISEASES. 
CHAPTER II. 
SARCOPTIC MANGE. 
SaRcopTic mange is an affection of the skin produced primarily by a mi- 
nute insect called the Sarcoptes Canis. This provokes a characteristic erup- 
tion, also severe itching, which causes the victim to scratch and bite, and in 
consequence an artificial eczema is developed. 
This insect, the acarus, an animal parasite, is supported by nourishment 
that it draws from the skin. The male is much the smaller, and remains in 
short burrows or vesicles, while the female tunnels the skin in long canals. 
The course of the latter is to seek a furrow on the skin, to which she at- 
taches herself, and by means of her jaws penetrates the outer layer or cuticle, 
and continues on until she reaches the deeper and softer layers, where she finds 
nourishment. She then proceeds to burrow and lay her eggs, with which she 
blocks behind her the passage that she has made. 
A young acarus develops from an egg in about two weeks. The number 
of eggs usually laid by a female is about sixty, and this production goes on con- 
tinually until she dies, which is generally in the third or fourth month. 
Around the furrows there appear pimples or slight elevations resembling 
flea-bites. These generally change to vesicles, but sometimes to pustules, 
when they discharge a small quantity of bloody pus, which, drying, produces 
thick dark crusts. 
In consequence of the scratching induced by the itching, the furrows are 
opened and the acariset free. The original eruption then gives place to eczema, 
with the irritation and itching that invariably attend it; and that disease 
spreads and increases in intensity. 
As soon as ont, the young acari run about on the surface, bore quickly 
beneath it, and in doing so add to the intolerable itching. 
After an extensive eczema has been developed, the presence of mange might 
be completely disguised ; but in the early stages of the latter it ought not to be 
difficult to determine the true nature of an attack. 
In sarcoptic mange the vesicles occur singly, not in groups, as in eczema; 
and they are pointed, not flat or rounded, like those of the latter disease. 
Itching is very severe both in mange and eczema, and intensified where 
these affections are combined; but in cases ot the former there are times when 
it is scarcely noticeable, whereas in the latter it is always very troublesome. 
