Etiology:  Chirodiscoides caviae is the fur mite of guinea pigs (see picture).

Incidence:  Mites are uncommon in guinea pigs.

Transmission: Transmission occurs by direct contact.

Distribution:  Mites are most numerous over the rump and flanks.

Clinical Signs:   Clinical signs are not usually observed. In heavy infestations, pruritus and alopecia may be evident.

Diagnosis:

Antemortem

1. Pluck hairs and examine subgrossly (dissecting microscope) or microscopically for mites or eggs.
2. 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 from the rump and perineum in a Petri dish. As the pelage cools, mites will migrate towards the tips of the hair shafts 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 brown specks on the black background.

Diagnostic Morphology: Elongated brown shield-shaped mite with 1st and 2nd pairs of legs adapted for clasping; posterior body is rounded in the female and blunted and triangular in the male.