Rodent Monitoring Services


Fur Mite
Myobia musculi inhabit the hair shafts and skin surface of the intrascapular and dorsal cervical regions. Myocoptes musculinus is found on the hair shafts and skin surface over the flanks and rump in low numbers, and are distributed over the entire dorsum in high numbers.
Evaluation:
Examine microscopically for mites or eggs
 Quantitative Polymerase Chain Reaction (qPCR):
 qPCR  of skin swab or cage swab. 
 Sample:
Skin swab or cage swab.

 

Myobia musculi is a fur mite that infests mice primarily. Fur mites live and breed on the infested animals fur, but descend to feed on the animals skin itself. The lifecycle of M. musculi is completed in around 23 days. The larval and nymphal period last around 15 days in total and adult mites appear within 16 days. Adult forms produce fertile eggs within 24 hours and these hatch into new larvae after 7 days. Transmission of fur mites is due to direct contact with an infested animal or the environment of that animal, i.e. uncleaned cage or bedding. Fur mites are visible on the fur when using stereomicroscopy or by direct examination of plucked tufts of fur. Symptoms and signs of mite infestations can range from nothing at all, to mild alopecia or to severe pruritus and ulcerative dermatitis, signs tend to worsen for older animals. Pruritic symptoms can lead to animals damaging their skin by scratching and this in turn can lead to secondary infections or worsening ulcerative dermatitis.

Myocoptes musculinus, a member of the family Myocoptidae, is a ectoparasitic (nonburrowing) fur mite that primarily infests wild house mice and laboratory mice, but has also been known to infect other mammals. There is evidence to suggest that the human is a mechanical carrier. It is the most common fur mite that has been identified among laboratory mice. Adult females tend to be between 0.30mm and 0.38mm; adult males are shorter, measuring between 0.16mm and 0.21mm. The Myocoptidae family comprises 6 genera, cumulatively giving rise to more than 50 species of mites. 5 of these genera are part of the subfamily Myocoptinae. The second subfamily, Dromiciocoptinae contains only one species: Dromiciocoptes brieni. The Myocoptes musculinus life cycle stages comprise of the egg, larva, two nymphal stages and adults; the eggs are attached to the proximal section of the hair shaft and hatch within 5 days. Identified on all parts of the body, Myocoptes musculinus undergo their entire life on the hair of the host and feed at the base of the hair. The full life cycle is complete within roughly 14 days. Transmission is said to require close or direct contact as well as hair shafts, and can ensue within a 24-hour period or less. From 4 ½ days after their birthing, young mice may well be infested from their mother (the mites cling to the vibrissae around the mouth of the young mice). Myocoptes musculinus has been affiliated with pruritus, alopecia and a collection of conditions including ulcerative dermatitis, hypersensitivity dermatitis and pyoderma. There are usually no symptoms, however, the loss of hair and erythema have been reported. A large number of mites causes skin irritation and skin bleeding. Increases in the size of the areas that are affected, debility and weight loss may lead to the death of the mouse.