THE SKIN—ITS ACCIDENTS AND ITS DISEASES.
MANGE.
This troublesome disease, which is the itch of the stable, generally preys upon the poorly nurtured, the aged or the debilitated. Neglect is the almost necessary associate of poverty; loss of pride attends loss of means, for seldom can the spirit of man brave the frowns of fortune. The want of emulation is always seen most emphatically without the doors of the home; the garden denotes the failure of industry, and the stable languishes under an absence of activity. The grooming is avoided; the horse's food is proportioned to the master's means, and is not given at regular hours; coarse diet and a filthy abode generate that weakness which will assuredly breed mange.
SYMPTOMS OF MANGINESS WHEN CAUGHT IN THE FIELD.
The disease, once developed, is highly contagious; all horses standing near the one affected, all that may touch it, or the shafts to which it was harnessed, or anything that has been in contact with the contaminated body, are inoculated. The very robust, to be sure, may escape; but this circumstance is to be regarded as the most stringent test of actual health rather than as the declaration of that state which the majority of mankind are pleased to term perfect condition. The animal which escapes must be of so sound a body as to afford no nutriment to the disorder which preys upon debility. Probably not one horse in ten thousand could resist so searching a test; the trial, however, after all, would be no more than a negative proof; and it is to be much regretted that science, up to the present time, has not discovered any means by which the presence of established health can be demonstrated.
Mange depends upon the presence of an insect which is classed with spiders, though to the uninitiated it looks, under the microscope, far more like a deformed crab. A representation of this parasite, very highly magnified, is here given, from Dr. Erasmus Wilson's paper upon the subject; and the reader may indulge his ingenuity by discovering its likeness to the spider.
THE MANGE INSECT.
The parasites are, when attentively searched for, to be recognized by the naked eye. Any man, by scratching the roots of the hair upon the mane of a mangy horse, may loosen a portion of scurf; let this scurf be received or cast upon a sheet of white paper. The paper then should be subjected to a strong light; the glare of the noonday sun is to be preferred, as warmth greatly influences the activity of the parasites. Numerous very small shining points may thus be seen moving about the mass in all directions. Those points are the insects, and, considering the easy means we now possess of demonstrating their existence, it seems astonishing that veterinary science was so long before it recognized the true source of the contagion. Even at the last moment, the sight was quickened by the research of a human physician, Dr. Erasmus Wilson; but after that gentleman soon followed Mr. Ernes, veterinarian, of Dockhead.