Mange: burrowing mites
Sarcoptes scabiei and Notoedres cati
Esther van Praag Ph.D.
Rabbits can be affected by mange, caused by burrowing
mites. Sarcoptes sp. is encountered all over the world, though not
with equal frequency. Rabbits in northern Europe and England are barely
affected by mange; in Israel and subtropical humid regions, they appear the
number one cause of skin parasitic infestations in rabbits. In the US it
varies according to the region. Burrowing mites present a zoonotic danger;
they can affect dogs, cats, and humans, causing a transient itching
dermatitis. The burrowing mange Notoedres cati
is occasionally observed to infest rabbits.
These parasites spread rapidly from one rabbit to
another, through nymphs and larvae that live on the surface of the skin. Only
the adult female will dig into the skin and make tunnels where it lays up to
5 eggs, with a maximum of 50 during her whole life. The larvae that hatch
from those eggs live the first stages of their life in those tunnels. Only
the male adults and older larvae live on the surface of the skin. The
complete life cycle from egg to adult lasts about 2 to 3 weeks. This should
be taken into account when treating a rabbit.
Symptoms and clinical signsWounds appear first on the lips and nose, later around
the head, neck, and sometimes around the genitalia. Burrowing mites (mange)
will lead to heavy scratching by the rabbit, which will also lick the
affected areas. This leads to alopecia (loss of fur). Often one can observe
the secretion of a watery stuff that forms crusts upon drying.
Self-mutilation will lead to wounds and secondary bacterial infection.
Severe infestation leads to anemia and leucopenia
(decrease of white cells in the blood). The rabbit becomes lethargic and can
die within a few weeks.
DiagnosisDiagnosis can be difficult and visual examination is not
always sufficient to confirm the presence of these mites. detection
methods include the tape method, skin scraping (shallow if fur mites are
suspected, deep if burrowing mites are suspected), or the vacuum aspiration
method on a filter paper. Samples from scraping or aspiration should be
spread on a microscope glass, dissolved in KOH, and examined under a
microscope. Great is the chance to see a at least
one mite or a larva or eggs. Fur can also be sampled, dissolved in KOH, and
examined under the microscope for the presence of eggs. If no mite is present
in the first sample, other places on the body should be checked. If the
presence of burrowing mites is suspected, but none found after a deep skin scraping,
a biopsy on the area suspected of mite infestation is advisable.
TreatmentMange is treated with 3 injections of ivermectin, one
every 14 days. The environment should be thoroughly cleaned, as the mite can
survive for weeks without the presence of the rabbit host. Wounds can be
treated with benzyl benzoate every 5th day.
Moxidectin
(Quest® or Equest® - Fort Dodge) has proved
efficacious in treating sarcoptic mange in rabbits.
It has so far not shown secondary effects in rabbits when administrated orally,
while secondary effects have sometimes been observed after subcutaneous
administration.
Sarcoptes scabiei
can infest dogs, cats, and man. If the sarcoptic
mite infestation is not resolved, the presence of dogs and cats, both
possible asymptomatic carriers, or of parasites that survived the treatment
should be considered.
If the affected rabbit presents severe anemia, a
transfusion of blood can be attempted from a healthy donor rabbit.
Burrowing mites (live on/in the skin) can fall off and
contaminate the environment. While treating for mites, careful cleaning of
the cage and environment is recommended. Treatment of the environment is
important (boric acid such as Fleabusters®; Vet-Kem Acclaim Plus® - Sanofi; Staykil® - Novartis; Indorex® -
Virbac; acaricide spray). When treating a carpet,
vacuum first in order to further penetration of the spray or powder.
Shampooing and steam cleaning are not ideal; their residual humidity can
increase the mite problem. During treatment of the environment, rabbits should
be kept in another part of the home to avoid the danger of contact with the
products.
For detailed
information on infestation by Sarcoptes scabiei in rabbits, see:
“Skin
Diseases of Rabbits”, by E. van Praag, A. Maurer and T. Saarony, 408
pages, 2010.
AcknowledgementsThanks
are due to K. Hermans, DVM (Kliniek
voor Pluimvee en Bijzondere Dieren, University
of Gent, Belgium) to Z. Aizenberg, DVM (The Koret
School for Veterinary Studies, The Hebrew University of Jerusalem, Israel),
to Michel Gruaz (Switzerland), and to Berend Bakker
(Indonesia) for the permission to use their illustrative material.
Further ReadingsBeck W. Farm animals
as disease vectors of parasitic epizoonoses and zoophilic dermatophytes and their importance in
dermatology. Hautarzt. 1999; 50(9):621-8.
Cerny
V, Rosicky B. Mammals as source of ectoparasites in
towns. Folia Parasitol (Praha). 1979; 26(1):93 5.
Isingla LD, Juyal PD, Gupta PP.
Therapeutic trial of ivermectin against Notoedres cati
var. cuniculi infection in rabbits.
Parasite. 1996; 3(1):87-9.
Nfi
AN. Ivomec, a treatment against rabbit mange. Rev Elev Med Vet Pays Trop. 1992; 45(1):39-41.
Wagner R, Wendlberger U. Field
efficacy of moxidectin in dogs and rabbits
naturally infested with Sarcoptes spp., Demodex
spp. and Psoroptes spp. mites. Vet Parasitol.
2000; 93(2):149-58.
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