Several authors consider the surface mite Psoroptes cuniculi to be so common in rabbits that all rabbits should be assumed to be carrying the mite unless proven otherwise. The mite may not cause any signs of disease however when it does it most often causes a scaly, crusting otitis externa and affected rabbits shake their heads, and scratch and flick their ears. Lesions occasionally spread to other parts of the head and body, and in severe cases secondary bacterial infection can complicate the clinical picture.
The mite is transmitted by direct contact from other rabbits, and indirectly through environmental contamination.
Treatment involves :
Environment - clean well, high dry temperatures (eg 1040F) are best at killing the mites, which can survive for up to 21 days off a host.
Rabbits - ivermectin at 200-400 micrograms per kg body weight by subcutaneous injection is recommended , or topical acaricides, although these drugs may not have a license specifically for use in rabbits for this purpose.
Other unlicensed avermectin products have been suggested by some authors BUT their safety has yet to be established
Selamectin: (Revolution (US) or Stronghold (Europe) - Pfizer, 6-18 mg/kg. A single topical (local) dose should be sufficient; if not, repeat after 30 days.