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8/9/2019 Sarcoptic Mange in Free-ranging Raccoon Dogs (Nyctereutes Procyonoides) in Japan (Pages 177–182)
Sarcoptic mange in free-ranging raccoon dogs (Nyctereutes procyonoides
) in Japan
HIROYOSHI NINO MIYA* and MUNE TSUGU OGATA†
*Department of Laboratory Animal Science, and †Veterinary Teaching Hospital, School of Veterinary
Medicine, Azabu University, 1-17-71 Fuchinobe, Sagamihara, Kanagawa 229-8501, Japan
(
Received
10 February
2004; accepted
1 November
2004)
Abstract
Sarcoptes scabiei
infestation was diagnosed in three freshly dead free-ranging raccoon dogs (
Nyc-
tereutes procyonoides
) in Kanagawa Prefecture, Japan. The dogs presented with an alopecic pruritic skin disease,
with signs of alopecia on the ears, muzzle, around the eyes, elbow, thigh and the neck, and hyperpigmented and
crusted skin lesions, which had a severe malodour. Skin scrapings revealed the presence of the mite Sarcoptes
scabiei
. Histopathology of lesions demonstrated marked acanthosis, hyperkeratosis, parakeratosis and fungalelements, which were subsequently identified as Acremonium
sp., Alternaria
sp. and an unknown fungus. Mite
segments were located mainly in the stratum corneum and also in the stratum granulosum. Tunnels could be
observed in the hyperkeratotic stratum corneum. Scanning electron microscopy (SEM) revealed the tortoise-like
Sarcoptes scabiei
with four long bristles, suckers and blade-like claws on legs 1 and 2, cuticular spines, prominent
body striations and a terminal anus. SEM also revealed an adult female mite digging a tunnel with the head
wedged into the very end of the closed burrow. Tunnels filled with eggshells, corneocyte debris and faecal pellets
were also observed.
INTRODUCTION
Sarcoptic mange is one of the most frequently diag-
nosed infestations in a wide range of domestic and wild
mammals throughout the world. Among canids in
Japan, sarcoptic mange (infestation with Sarcoptes
scabiei
) has been reported in dogs (
Canis familiaris
),
1
foxes (
Vulpes vulpes
)
1
and raccoon dogs (
Nyctereutes
procyonoides
).
1,2
The prevalence of scabies in raccoon
dogs has been shown to be high in urban and suburban
areas over the past decade in Kanagawa Prefecture,
Japan.
1
Despite being a relatively common cutaneous
disease among raccoon dogs, descriptions of the his-
topathological changes associated with the infestationin raccoon dogs are limited. The female mite lives
within the stratum corneum and burrows down to the
stratum granulosum to feed on the tissue fluid oozing
from cells and cellular particles.
3
The aims of this case
report were to describe the lesions associated with
infestation by sarcoptic mange mites using routine
histopathology and scanning electron microscopy
(SEM) to provide a better understanding of the mite’s
habitat.
CLINICAL, HISTOPATHOLOGICAL
AND ULTRASTRUCTURALFINDINGS
Between September and December 2003, three free-
ranging raccoon dogs (adult male) were found dead next
to a dirt road in the suburban areas of Sagamihara City
(139
°
22
′
E, 35
°
34
′
N) in Kanagawa Prefecture, Japan.
They had died due to vehicular collision. All three dogs
had skin lesions comprising moderate to severe alopecia
and extensive dermatitis over the ears, muzzle, around
the eyes, elbow, thigh and the neck, and had a severe
musty malodour (Fig. 1). The alopecic skin was markedly
corrugated, thickened and covered by greyish plaquesof keratinous crusts (Fig. 2). Skin scrapings collected
into 10% KOH revealed eggs, nymphs, larvae and oval-
shaped adult mites that had angular scales, thick spines
and prominent fine striations on the dorsal idiosoma,
features that were consistent with Sarcoptes scabiei
. To
allow detailed examination, mites were examined as
whole mounts in balsam (Fig. 3). The number of mites
including nymphs and larvae was up to 82/cm
2
in severely
infested areas of skin. Skin scales were also collected
for fungal culture and grown on potato dextrose agar
with added chloramphenicol and cycloheximide at
25 °
C. Fungi identified on the basis of morphological
appearance included Acremonium
sp., Alternaria
sp.and an unknown fungus.
Skin specimens were excised and fixed in neutral-
buffered 10% formalin, sectioned serially at 5 µ
m and
Correspondence: H. Ninomiya, Department of Laboratory Animal
Science, School of Veterinary Medicine, Azabu University, 1-17-71
the dorsal idiosoma may play a role in preventing mites
from being pushed back by the epidermal outward flow.
The female mite digs her burrows by physically forcing
her way between the corneocytes, rather than chewing
a passage in termite fashion.
13,14
She ploughs with two
sets of powerful hind legs, and forward progress is
aided by the jaws and two cutting blade-like claws onthe elbows of the first two pairs of legs, similar to a
mole.
13,14
Scabiei eggs in the burrow are glued to each
other and on the burrow floor by a cement-like sub-
stance secreted by the ‘glue gland’ along the oviduct.
13
In addition, they are tied with fine threads to the bur-
row floor, presumably so as not to be dispersed.
This SEM study has clearly shown the mite and its
habitat and these ultrastructural observations will shed
light on the outlines seen under the light microscope by
clinicians. Description of the disease as it occurred in
the raccoon dog is very similar to what would corre-
spond to an epizootic of sarcoptic mange in humans,
9,10
dogs,
4
foxes,
5
ibex,
6
pigs
7
and wombats.
8
Sarcoptic
mange mites from different species tend to be morpho-
logically indistinguishable
3
and transmission of S. scabiei
var. canis
to raccoon dogs has been suggested.
1,2
Hence,
it is possible that the mites examined in this study could
be S. scabiei
var. canis
. Further investigations regard-
ing ‘variability’ of the mite among hosts are indicated.
REFERENCES
1. Ishihara T, Hirotani H. Problems caused by wild animals.
In: Mammals. Tokyo: Yurindo, 2003: 113–16 (in Japanese).
2. Takahasi M, Nogami S, Misumi H et al. Mange causedby Sarcoptes scabiei
(Acari: Sarcoptidae) in wild raccoon
dogs, Nyctereutes procyonoides
, in Kanagawa prefecture,
Japan. Journal of Veterinary Medical Science 2001; 63:
457–60.
3. Bornstein S, Mörner T, Samuel WM. Sarcoptes scabiei
and
sarcoptic mange. In: Pybus J & Kocan AA eds. Parasitic
Diseases of Wild Mammals, 3rd edn. Ames: Iowa State
University Press, 2001: 107–19.
4. Morris DO. A histomorphological study of sarcoptic
acariasis in the dog: 19 cases. Journal of the American
Animal Hospital Association 1996; 32: 119–24.
5. Little SE, Davidson WR, Rakich PM et al. Responses of red foxes to first and second infection with Sarcoptes sca-
biei
. Journal of Wildlife Diseases 1998; 34: 600–11.
6. León-Vizcaíno L, Ruíz de Ybáñez MR, Cubero MJ et al.
Sarcoptic mange in Spanish ibex from Spain. Journal of
Wildlife Diseases 1999; 35: 647–59.
7. Sheahan BJ. Pathology of Sarcoptes scabiei
infection in
pigs. Journal of Comparative Pathology 1975; 85: 87–95.
8. Skerratt LF, Middleton D, Beveridge L. Distribution of
life cycle stages of Sarcoptes scabiei
var wombati
and
effects of severe mange on common wombats in Victoria.
Journal of Wildlife Diseases 1999; 35: 633–46.
9. Van Neste D, Lachapelle JM. Host–parasite relationships
in hyperkeratotic (Norwegian) scabies: pathological andimmunological findings. British Journal of Dermatology
1981; 105: 667–78.
10. Arlian LG, Bruner RH, Stuhlaman RA et al. Histo-
pathology in hosts parasitized by Sarcoptes scabiei
. Journal
of Parasitology 1990; 76: 889– 94.
11. Burgess I. Sarcoptes scabiei
and scabies. Advances in
Parasitology 1994; 33: 234–92.
12. Leiferman KM. A current perspective on the role of
eosinophils in dermatologic diseases. Journal of the
American Academy of Dermatology 1991; 24: 1101–12.
13. Shelly WB, Shelly ED. Scanning electron microscopy of
the scabies burrow and its contents, with special reference
to the Sarcoptes scabiei
egg. Journal of the American
Academy of Dermatology 1983; 9: 673–79.14. Mellanby K. Biology of the parasite. In: Otkin M,
Maibach HI, Patish LC & Schwartzmann RM eds.
Scabies and Pediculosis. Philadelphia: J.B. Lippincott Co.,
1977: 8–16.
Résumé
Une infestation par Sarcoptes scabiei a été diagnostiquée chez trois raccoon (
Nyctereutes procyonoides
)
à la préfecture de Kanagawa, Japon. Les chiens présentaient une dermatose prurigineuse et alopéciante, avec une
alopécie des oreilles, du chanfrein, autour des yeux, sur les coudes et le cou, et des lésions croûteuses hyperpig-
mentées et malodorantes. Les ralages cutanés ont montré la présence de Sarcoptes scabiei
. L’Histopathologie
des lésions a montré une acanthose marquée, une hyperkératose, une parakératose et des éléments fongiques qui
ont été identifiés comme des Acremonium
sp., Alternaria
sp. et une espèce non connue. Des segments d’acariens
étaient localisés dans le stratum corneum et dans le stratum granulosum. Des tunnels ont été observés dans le
stratum corneum hyperkératosique. Une microscopie électronique (SEM) a montré un Sarcoptes scabiei
avec quatre
longs poils, des ventouses et des griffes sur les pattes 1 et 2, des épines cuticulaires, des stries proéminentes et un
anus terminal. En outre, la SEM a montré une femelle adulte creusant un tunnel avec la tête dirigée en profondeur.
Les tunnels étaient remplis d’oeufs, de débris de cornéocytes et de déjections fécales.
Resumen
Se diagnosticó una infestación por Sarcoptes en tres mapaches (Nyctereutes procyonoides) de
muerte reciente, de vida libre en la prefectura de Kanagawa, Japón. Los mapaches presentaban una enfermedad
prurítica y alopécica, con alopecia en los oídos, hocico, alrededor de los ojos, codo, muslo y cuello, y lesiones
hiperpigmentadas y costrosas con un fuerte olor. Los raspados cutáneos revelaron la presencia del ácaro
Sarcoptes scabiei
. La histopatología mostró acantosis marcada, hiperqueratosis, paraqueratosis, y elementos
fúngicos que fueron identificados posteriormente como sp. de Acremonium, Alternaria y un hongo desconocido.
Los segmentos de ácaro se situaban principalmente en el estrato córneo y también en el granuloso. Los túnelesse podían observar en el estrato córneo hiperqueratótico. La microscopía electrónica de barrido (SEM) reveló
un ácaro de Sarcoptes
en forma de tortuga, con cuatro cerdas largas, chupadores y garras en forma de cuchilla
en las patas 1 y 2, las espinas dorsales cuticulares, estriaciones prominentes del cuerpo, y un ano terminal.
8/9/2019 Sarcoptic Mange in Free-ranging Raccoon Dogs (Nyctereutes Procyonoides) in Japan (Pages 177–182)