Etiology:  Radfordia ensifera isthe fur mite of rats.

Incidence:  Incidence of infection is low.

Transmission:  Fur mites are transmitted by direct contact.

Distribution:  Radfordia ensifera are found in the intrascapular and dorsal cervical regions.

Clinical Signs:  Clinical signs are not usually observed unless there is a heavy infestation.

Diagnosis:

Antemortem

1.  PCR of skin swab or cage swab.  This is the most reliable method for detection.

2. Pluck or brush hairs and examine subgrossly (use a dissecting microscope) or

microscopically for mites or eggs.

3. Run cellophane tape against the grain of the fur, place on a slide and examine

microscopically for mites or their eggs. This method is not very reliable for detection.

Postmortem

1. Place pelage (fur) samples collected in a Petri dish. As the pelage cools, mites will migrate towards the tips of the hairshafts and be visible with a dissecting microscope.

2. Place pelage samples on black construction paper. As the pelt cools, the mites will crawl away, and be visible as white specks on the black background. *Be sure to ring the edges of the construction paper with double stick tape, so that the mites do not escape the area.

Diagnostic Morphology:  Paired, equal-length empodial claws on the 2nd leg.