Itch mite

(Psorobia ovis; formerly Psorergates ovis)

The itch mite lives on the skin of sheep and goats, causing intense irritation. Sheep or goats rub and scratch, sometimes causing severe fleece and fibre damage.

Itch mite is described on the WormBoss site only because it has been controlled effectively by macrocyclic lactone (ML or ‘mectin’) sheep drenches (ivermectin, abamectin and moxidectin) and the goat drench, abamectin.

Since the introduction of those drenches in the 1980s, signs of itch mite have become infrequent.

The signs of itch mite are very similar to that of lice or grass seed irritation, and should be suspected only after these are ruled out. Diagnosis is not easy, as the itch mite is even harder to see than lice and requires a skin scraping, generally from a number of sheep or goats (not just a badly affected one), and microscope examination.

If itch mite is suspected, most farmers choose to simply use an ML drench as their next worm treatment for the flock or herd. A specific treatment just for itch mite cannot be justified.

Itch mite may not be able to be eradicated, but as they only build up very slowly, ML treatments each few years are sufficient to keep them well under control.