Moist dermatitis, green fur syndrome, caused by
Pseudomonas aeruginosa
Esther van Praag, Ph.D.
|
This skin disorder is
caused by bacteria like Staphylococcus spp., Streptococcus
spp., and mainly Pseudomonas aeruginosa. The
later is a Gram-negative, opportunistic pathogen that lives in aerobic and
poor nutritional conditions (the bacterium is able to grow in distilled
water). The bacterium produced 2 pigments, pyoverdin
and pyocyanin, when living in an environment with a
low content of iron, which color the hair and pus oozing out of infected skin
or abscesses in a characteristic blue-green. Exudative (relating to
the oozing of fluid and other materials from cells and tissues) moist
dermatitis is mainly observed in rabbits exposed to constant moisture, for
instance: • Leaking water bottles, or inadequate
crock; • Overweight; • Large dewlap (fold of skin which hangs
under the throat of female rabbits); • Ptyalism, due to (severe) dental problems,
leading to excessive production of saliva.
Clinical signs and diagnosis
The clinical signs should be sufficient for diagnosis.
Even so, a bacterial culture is advisable, as a precautionary measure. The
cultures of isolated bacteria will help identify the bacterium properly.
Sensitivity tests will, furthermore, help determine the most efficacious
antibiotic. The bacterium is indeed difficult to treat, as it has naturally
acquired resistance to many antibiotics, while living in the soil, among
bacteria, yeast and fungi that secrete natural antibiotics. Parts of the body affected by this bacterium are the
dewlap, and the abdomen. Lesions are localized and diffuse and the skin is
erythematous and moist. It may be accompanied by the presence of deep ulcers
or abscesses. Secondary bacterial infection is possible when the condition is
left untreated, with the formation of skin abscesses.
TreatmentThe fur is carefully clipped
and the inflamed skin is treated with topical antibiotics. If the infection
by Pseudomonas sp. is severe, the topical treatment should be
accompanied by an aggressive systemic antibiotic therapy. The most effective antibiotics
remain fluoroquinolone (e.g. enrofloxacin), gentamycin, and amikacin. Since
some strains are resistant to several antibiotics, a culture accompanied by
an antibiotic sensitivity test should be done. While treating the skin problems,
it is necessary to look for the primary cause of infection. This includes: • Meticulous inspection of the teeth of the
rabbit, in order to detect defects of the incisors (malocclusion), the
presence of spurs or of a tooth root abscess; • Verification of the drinking habits of the
rabbit (crock or water bottle); • Analysis of the water that the rabbit is
drinking for the presence of Pseudomonas sp. Infections should not be
neglected and left untreated. After the primary invasion of the skin, Pseudomonas
bacteria tend to invade the tissues deeper and will use the circulatory blood
system to disseminate throughout the body.
AcknowledgementThanks
are due to Dr. M. Schoenbaum (Ministry of
Agriculture, Veterinary Services, Israel) for the
permission to use his pictures. Further informationGaribaldi
BA, Fox JG, Musto DR. Atypical moist dermatitis in
rabbits. Lab Anim Sci. 1990 Nov;40(6):652-3. O'Donoghue PN, Whatley BF. Pseudomonas aeruginosa in rabbit fur. Lab Anim. 1971 Oct;5(2):251-5. Schoenbaum
M. Pseudomonas aeruginosa in rabbit fur. Lab Anim. 1981
Jan;15(1):5. Wellisch
G, Cohen E, Cahane Z, Kedar S, Fradis M, Podoshin L. Distribution of Pseudomonas
aeruginosa serotypes in Israel. Microbiol Immunol. 1980;24(3):233-35.
Williams
CS, Gibson RB. Sore dewlap: Pseudomonas
aeruginosa on rabbit fur and skin. Vet Med Small Anim
Clin. 1975 Aug;70(8):954-5. |
e-mail: info@medirabbit.com
