AN UNUSUAL CASE OF PSOROPTES CUNICULI IN A RABBIT
A Chadwick BVSc MRCVS Cert VD
Species, breed, age and sex of animal
The rabbit was a female 5 year old black domesticated rabbit.
The rabbit was presented because of excessive scaling around the
perineum and ventrum. It was lethargic and anorexic.
The animal had been presented a month earlier with crusting
lesions in the ears which had been treated with 0.5% diethanolamine fusidate (Canaural,Leo).
This had apparently resolved the problem in one week.
The owner had noticed a few days before presentation that the
rabbit was lethargic and noticed the crusting lesions after
turning the animal onto its back.
No abnormalities apart from the dermatological ones were seen.
A dermatological examination demonstrated 2 separate crusting lesions: one around the perineum and
one in the mid-ventrum area. These areas were pruritic and painful to the rabbit. Anaesthesia using a
combination fentanyl citrate/fluanisone (hypnorm, Janssen) & diazepam (generic) was performed at a
dose rate of 0.3mL/kg i.m.+2mg/kgi.p. respectively.There was a strong odour from these crusting lesions.
The crusts were removed to reveal an intensely erythematous, alopecic area.
Photograph of the erythematous region after the crusts were removed.
Chemical burning of small areas.
Laboratory and other diagnostic tests
Skin scrapings were taken. Large numbers of Psoroptes cuniculi were seen.
Diagnosis & prognosis.
A diagnosis of Psoroptes Cuniculi infestation was made. The prognosis was good since
treatment was given in the winter.In the summer months fly strike is a possible complication but it was not
a factor in this case.
Ivermectin at the recommended dose rate of 400 ug/kg(Ivomec, MSD Agvet) was administered
subcutaneously. (Wright and Riner 1985, Pandey 1989 and Curtis et al 1990)
Ivermectin has been shown to be highly effective against Psoroptes Cuniculi. (Wilkins et al 1980).
The owner was advised to burn all the rabbit's bedding and disinfect and rinse the hutch well.
She was asked to represent the animal in 18 days for inspection and a 2nd injection of ivermectin since
the life cycle of P. Cuniculi is 3 weeks (Sweatman, 1958)
Re-inspection and final outcome
The rabbit had improved greatly over the 18 day period. It was much more lively and there were no
pruritus, crusts or erythematous lesions around the perineum and ventrum. Hair brushings were negative
on microscopic examination.
Treatment with ivermectin seemed to be 100% effective in reducing the psoroptic mite population.
Careful cleaning of the hutch was also performed to try to reduce any possibility of te-infestation
from the environment. However, it is nearly impossible to remove all dander and dust from around the
hutch. The distribution of the lesions and the non-involvement of the ears were also interesting.
The standard texts do not mention non aural involvement (Beynon and Cooper, 1991 ). There is a report
of two cases where pruritus and erythema affected face, ventrum and genitalia similar to this case
BEYNON, P.H. and COOPER, J.E.(1991)
Rabbits. In Manual of Exotic Pets 2nd edn. pp69-81. BSAVA.
CURTIS, S., HOUSLEY, R. and BROOKS, D. (1990)
Use of Ivermectin for treatment of ear mite infestations in rabbits. JAVMA. 196,1139-1140.
Effect of Ivermectin on the ear mange mite, Psoroptes Cuniculi, of rabbits. Br Vet J 145,54-56.
On the life history and validity of the species in Psoroptes, a genus of mange mites.
Canadian Journal of Zoology 36, 905-929.
WILKINS, C.A., CONROY, J.A., OISHANNEY, W.J., MALATE8TA, P.F. & EGERTON, J.R.(1980)
Treatment of Psoroptic Mange with Avermectins. Am J Vet Res 41,1112-2113.
WRIGHT, F.C & RINER, J.C.(1985)
Comparative efficacy of injection routes and doses of ivermectin against Psoroptes in rabbits.
Am J Vet Res 46,752-754.
YEATTS, J.W.G. Rabbit mite infestation. Vet Rec 134;360, 1994.
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