Case report: Atypical treponematosis - rabbit syphilis
in a rabbit
Tal Saarony
(Thank you for the permission to use the following text and
pictures)
Warning: this
file contains pictures that may be distressing to some persons
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The 2 most important facts about rabbit syphilis are: 1. That it is completely treatable and curable; 2. That it is not zoonotic and cannot be transmitted to humans. Rabbit syphilis is a disease
caused by the bacterium Treponema cuniculi. It can be transmitted
sexually, but has also been seen in rabbits that were living singly, having
had no contact with other rabbits, and in rabbits that were sharing space
with unaffected rabbits. It is believed that the disease was transmitted to
these rabbits at birth or via the mother's milk while nursing. In some
rabbits the bacterium may remain dormant for long periods of time, even
years, and the affected rabbit will show no clinical signs until a stressful
event occurs, causing the infection to erupt. The incidence of syphilis in
house rabbits is not known, but it is likely more common than previously
thought. It is, therefore, important to be aware of the clinical
characteristics of the regular and atypical forms as well as of the easy
availability of treatment. Clinical signs The typical form of syphilis
affects the mucocutaneous junctions of the genitalia, the anus and/or the
face, mainly around and on the eyelids and nose. Lesions develop slowly. The
skin becomes crusty and ulcerated. The secretion of a pus-like exudate and
bleeding can occur. Due to slow immune response to the bacterium, the
infection can spread to the surrounding areas and other
susceptible regions on the body (e.g., from the anus/genitalia to
the face) when left untreated. Over the last years, an
atypical form of treponematosis has been observed in rabbits, in which
clinical signs are seen only on the face and not on the genitals/anus. The
affected area will exhibit lesions that will develop into crusts and, if left
untreated, will spread. The lesions may become raw, inflamed, or may bleed or
exude a discharge. Treatment Syphilis bacteria will only be
killed with injected penicillin G (benzathine/procaine: 42.000 - 84.000
UI/kg), at intervals of 5 to 7 days, continued 4 - 5 weeks. The importance of
injected administration must be emphasized here: rabbits should NEVER
be administered penicillin orally. It is important to monitor the
rabbit's eating. As the dying bacteria release toxins inside the rabbit's
body, the appetite may be affected. Inappetence can last 2 - 3 days, but the
rabbit usually begins eating again on its own. It is essential that the
antibiotic is not stopped; the rabbit should be encouraged to eat, tempted
with favorite foods, and given a lot of attention and love to motivate it to
eat. References 1. Saito K., Tagawa M., and Hasegawa A. Rabbit Syphilis Diagnosed
Clinically in Household Rabbits J. Vet. Med. Sci. 65(5): 637-639, 2003 2. Saito K., Tagawa M., and Hasegawa A. RPR Test for Serological
Survey of Rabbit Syphilis in Companion Rabbits J. Vet. Med. Sci. 65(7):
797-799, 2003 3.
Bellangeon M. Tréponématose chez le Lapin de Compagnie
PASE 2, deuxième trimestre 2001 4.
Saunders RA, Davies RR.
Notes of rabbit internal medicine. Oxford,
UK: Blackwell Publishing; 2005 5. Quesenberry KE, Carpenter JW. Ferrets, rabbits and rodents.
Clinical Medicine and Surgery. St Louis, USA: Saunders; 2004 Gozal's syphilis The
cast of characters:
On Feb. 9th, 2007 I first
discovered what appeared to be an injury at the corner of Gozalʼs eye. I believed it resulted from an altercation
during a bonding session with Tinok. It resembled a crusty eye discharge.
Later it began to appear inflamed. The following picture was
taken on March 5th:
Motek was grooming the eye
excessively and it was believed she was not allowing the wound to heal. The
wound was crusted over, then, suddenly, a crater appeared (the ulceration
that formed underneath the crust, ± 1cm into the skin). It was not clear
whether the crust fell off spontaneously or was pried off by Motek. They were
separated. Gozal was being treated with an antibiotic eye ointment which had
no effect on his condition. The wound also began bleeding. April 18th:
April 20th:
May 8th:
May10th:
Around that time Gozalʼs nose presented with crusts as well, though to a much
lesser degree; I did not manage to take clear pictures. The crusts on his
face extended approximately 1 cm deep into the skin.
Gozal was injected with a
vitamin solution (B1, B2, B6, B12,
A, D, and E), and with the antibiotic sulfamonomethoxine; Panolog, an
ointment used for external ear infections and skin disorders, was applied to
his crusts. The Panolog application was to be continued at home. Gozal’s wound was debrided by
his vet and the sample crusts inspected under the microscope. Nothing specific was found. A
fungal culture was taken and sent to a lab. No fungi were found. The skin condition continued to spread. New crusts appeared. May 13th:
May 15th vet visit: Gozal
appeared to be responding to the medication. His tear ducts were flushed
under anesthesia and his teeth checked for abnormal root growth that might
affect the eye. The vet considered a nasolachrymal canal infection (infection
of the canal containing the tear ducts). Gozal was injected with the same
vitamin solution as before and with the antibiotic chloramphenicol, and more
Panolog was applied. At that point no diagnosis had yet been arrived at. I
was to continue applying the Panalog at home and to monitor Gozal for
appetite, output, behavior, and the condition of the skin. May 16th:
Crusts on the nose (arrows):
May 22nd: The vet was satisfied with
Gozal’s progress; he observed new hair growth. He applied more ointment and
dripped a fluid to protect from further infection into the eye. More vitamins
were injected as well as chloramphenicol. May 29th: The vet felt Gozal’s condition
had worsened. The crusts had spread. He collected a skin scraping sample, but
was not able to identify anything under the microscope. He ruled out a fungal
infection. Gozal’s tear ducts were flushed under anesthesia once again. Gozal
was injected with Baytril (enrofloxacin) and a fluoroquinolone preparation
(an antibiotic) was applied to the affected areas. The wound was cultured and
the sample sent to a lab for analysis. May 31st, the lesions/crusts
have spread downward:
Around this time, a friend who
is a vet with great interest in rabbits, and who had been following Gozalʼs condition via emails and pictures, suggested rabbit
syphilis. The information with articles and treatment options was brought to
Gozalʼs vet who, at first,
dismissed it. However, as Gozalʼs condition was not improving with the
administered treatments and all tests were returning inconclusive, he agreed
to try treating Gozal for the disease. In retrospect this explains why
remission was observed after each administration of antibiotics.
Fluoroquinolone antibiotics are known to
suppress the clinical signs of treponematosis infection but do not
kill the Treponema cuniculi bacterium. Recurrence is observed
immediately after the treatment is stopped, often a more severe form than
before. On June 1st Gozal
got the first shot of penicillin. June 4th, immediate, great
improvement:
June 9th:
July 7th:
Healed! There is still a small area at the corner of the eye where hair
doesnʼt grow and a cut on the eyelid where
the skin did not regenerate fully (arrows), but Gozal is 100% healthy. In
other spots of previous deep skin lesions the hair grew back white.
Gozal received a total of 5
injections of penicillin G, a week apart, during 5 weeks. After the first
shot he experienced loss of appetite for about 36 hours, but resumed eating
on his own. During his illness he never stopped eating and never showed any
signs of pain or discomfort. Tinok was not infected; 4
months after first discovering Gozal’s eye, I noticed that Motek’s nose
looked very pink and there was a small protuberance of what appeared to be a
raised tuft of hair on the left side of her face.
The protuberance was softish, with clumped hair covering it. It
was not crusty. While the lump did not look or feel like the crusts Gozal had
exhibited, the pink nose did appear similar. The vet concluded the lump was
the same as Gozal’s and diagnosed her with syphilis as well; however, the
diagnosis was based strictly on a visual examination and on her proximity to
Gozal and previous extensive grooming of his infected skin. No tests were
performed on her. She received 2 pen G injections, a week apart. Following
the first injection the lump disappeared and the nose improved. She was back
to normal after the second injection.
Since Gozal had been
exclusively with Motek and I for a year and a half, and a bit with Tinok, and
was already over 3 years old before showing any clinical signs, it is
believed that the disease passed to him from his mother at birth or while
nursing on her milk. It lay dormant and asymptomatic and most likely erupted
due to the stress of bonding. Gozal dislikes Tinok and to this day they are
not bonded. At the time I was conducting daily bonding sessions. Of my 3
Gozal is the most sensitive and prone to stress, and his body and immune
system reacted by developing the disease. Gozal, September 18th,
2009.
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Thank you to Gozal for
his patience and his cooperation in taking the numerous pictures.
e-mail: info@medirabbit.com
