Demodex ovis: Demodectic mite.

General Description: Cigar-shaped mites, about 0.25 mm. Long, with 4 pairs of stumpy legs.

Life Cycle: Unknown

Location: Hair follicles and sebaceous glands of skin. Favoured areas are eyelid, prepuce of male, and vulva of female.

Geographical Distribution: Although the distribution is not well-known, sheep in the United States (New York) and England have been found to carry Demodex ovis.

Significance: Demodectic mange is not known to be a problem in sheep.

Effect on Host: Demodectic mange; follicular mange; chronic inflammation with thickening of skin. Skin becomes scaly and loss of wool is possible. Demodectic mites may exist in skin without causing damage. Scaly, reddened skin, especially of eyelids, is possible sign.

Diagnostic Information: Cigar-shaped mites seen microscopically in skin scrapings; however, evidence shows that Demodex may exist in normal, healthy skin without apparent signs.

Control: Insecticide ointments or systemic chemicals may be effective, but control is difficult. Demodex is transmitted by direct body contact.

Demodex - adult