Mites - Mice

Fur Mites

Myobia musculi, Mycoptes musculinus and Radfordia affinis are species of mite found in the mouse — Myobia musculi being the most common.

Signalment

Any mouse may be affected, however it has been reported that black mice are more susceptible to infection. Infection is by direct contact, and the mite spends the entirety of its lifecycle on the host.

Clinical Signs

With heavy infestations, lesions appear as patchy alopecia and excoriation, particularly on the face, head and between the shoulder blades. Ulcerative dermatitis ad secondary bacterial infection can also occur following self-trauma. There may be no clinical signs if the infestation is of a low level.

Diagnosis

Direct visualisation of the mites or eggs on the fur or skin.

Treatment

Two injections of Ivermectin administered subcutaneously 7 days apart are reported to be effective. Repeat treatment is necessary due to the lifecycle of the mite, as treatment may not kill unhatched eggs. Oral solutions and topical applications of Ivermectin have also been reported as treatments. The environment should be treated with insecticidal sprays.

References

Bond, Hendricks, Loeffler (2009) Veterinary Dermatology RVC Intergrated BVetMed Course, Royal Veterinary College

Merck & Co (2009) The Merck Veterinary Manual (Ninth Edition), Merial