Copyright 1999

YEAST
Malassezia Pachydermatis

YEAST
Several Malassezia Pachydermatis organisms with epithelial cells

PARASITE
Otodectes mites

BACTERIA
Staphylococcus intermedius. The organisms are shown on a background of debris

BACTERIA
Proteus spp. with an epithelial cell. These organisms stain red with Gram's stain

BACTERIA
Pseudomonasspp. bacteria with an epithelial cell. Compare with the previous figure, which is stained with Diff-Quick. Pseudomonasspp with appear identical to Proteusspp under microscopic examination. Either organism will stain blue with Diff-Quick or red with Gram's stain

WHITE BLOOD CELLS
With certain infections, white blood cells may be present. This figure shows several degenerating white blood cells and DNA strands from damaged cells.

PERFORMING A ROLL SMEAR

1. Cotton swabs and slides are needed to perform a roll smear.
2. The cotton swab is gently placed in the ear canal to recover a
sample of the exudates. If otodectic mange is suspected, mineral
oil should be placed on the cotton swab.
3. The cotton swab is then rolled on the slide. A consistently thin
smear should be made for bacteria and yeast. A thick smear
should be made for Otodectes.
4. The slide is now ready for examining mites. For microbiologic or
cytologic evaluation, the slide must be stained.

STAINING SLIDES

1. For oily exudates, the slide should be heated from the bottom.
2. Initially, Gram's stain should be used to differentiate
gram-positive form gram-negative rods. Gram negative cocci are
not found in the ear, and Malassezia organisms are either
gram-positive or gram-negative. No staining is required for
evaluation of Otodectes.
3. Diff-Quick (or an equivalent stain) can be used to reevaluate roll
smears or to evaluate exudates taken at follow-up visits.
4. The technique recommended by the manufacturer of the stain
should be followed.

By Otomax