DEMODECIC MANGE.
This mange is produced by parasites of the family Demodecidæ (Demodex folliculorum), which live in the hair follicles and sebaceous glands of several species of mammals.
DEMODECIC MANGE IN THE OX.
This was described in 1845 by Gros, and in 1878 was found by Faxon in Illinois in the skins of cows prepared for tanning. It has not been met with in France. The skins examined by Faxon showed numerous rounded enlargements, resulting from dilatation of the hair follicles in the regions of the neck and shoulders.
By pressing on these enlargements a whitish, greasy, sebaceous material was ejected, very rich in demodectes.
DEMODECIC MANGE IN THE GOAT.
Fig. 263.—Demodex of the pig, magnified 250 diameters. (After Railliet.)
This was first noticed by Niederhaüsern, at the Bern Veterinary College, in a goat which showed little nodosities over different parts of the trunk, varying in size between that of a pea and that of a hazel-nut. By forcibly compressing these enlargements a yellowish-grey semi-solid material, containing a considerable number of demodectes, was caused to exude.
In 1885 Nocard and Railliet found the same parasite in a young he-goat; the pustules were spread over the sides and flank. Treatment consists in opening the pustules and dressing them a few times with an anti-parasitic lotion.