Transcript Anal and Perianal dermatosis in the dog

Skin scrapes compared to hair plucks
for diagnosis of Canine Demodicosis
L. BECO, Cabinet Vétérinaire, Spa, Belgium
J. FONTAINE, Clinique Vétérinaire, Bruxelles, Belgium
K. BERGVALL, Department of Clinical Sciences, University of Agriculture, Uppsala, Sweden
C. FAVROT, Clinic for Small Animal Internal Medicine, Dermatology Unit, Vetsuisse Faculty, Zurich, Switzerland
Positive samples / clinician
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Multicentre prospective study
Comparison of sensitivity of skin
scrapes and hair plucks (with or
without skin squeezing) for
collection of Demodex mites in
dogs with demodicosis
# of dogs
Objectives
Methods
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161 dogs with localized or
generalized, juvenile or adult onset
demodicosis were included at their
initial examination
Standardized area was determined
for each method of sampling
Deep skin scrapes and hair plucks
were performed on a non prepared
skin and after skin squeezing
Material was collected on a glass
slide and put in a chloral
lactophenol or mineral oil drop.
The slides were examined with
light microscopy with a 100X
magnification
Specimens were classified as
positive (demonstration of
Demodex adults, larvae or eggs)
or negative
60
50
40
30
20
10
0
Summary
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LB
JF
CF
KB
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Total of positive samples
200
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150
# of dogs
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Skin Scrapings (SS)
SS + Squeezing
Hair Pluckings (HP)
HP + Squeezing
100
161 dogs were included in the
study (localized demodicosis
25%, generalized 75%)
No statistical difference was
observed between skin scrapes
and hair plucks with respect to
proportion of Demodex positive
specimens
Squeezing the skin prior to
scraping significantly increased
the number of positive
specimens
Sensitivity of the technique
varies between clinicians
Conclusions
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0
SS
HP
SS + Sq
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Hair plucks (a technique easy
to perform and well accepted
by dogs and their owners) can
be recommended for
diagnosing canine
demodicosis
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However, skin scrapes after
squeezing appear to be the
most sensitive method to
collect Demodex mites
HP + Sq
Type of Demodicosis
SS
25%
Localized
> 1 year
< 1 year
Generalized
64%
75%
36%