Occasionally, rabbit populations are affected by rabbit syphilis (spirochetosis). This condition is caused by the bacterium Treponema cuniculi. The disease gets its name due to its similarity to syphilis in humans (Treponema pallidum).
Symptoms: How Can I Recognize Syphilis in Rabbits?
Affected rabbits may exhibit the following:
Swelling and redness (inflammation) or even pus in the genital area, and/or
Inflammation and crusts around the nose (often mistaken for rabbit snuffles), and/or
Inflammation and crusts on the lips,
Rarely, inflammation and crusts around the eyes, and occasionally around the mammary glands.
Very rarely, other areas may be affected first.
When there is inflammation in the genital area, diarrhea is often a secondary symptom.
These inflammations progressively spread and, if left untreated, can lead to death in weakened animals. Immunocompetent but untreated rabbits often experience recurring symptoms over a long period or have the disease persistently.
Typically, affected rabbits initially show skin changes in only one area (either on the nose or the genital area).
The diagnosis is usually made based on the clinical presentation as a suspected case. However, it is also possible to confirm the pathogen through a blood test, though this process takes some time (approximately two weeks).
Differential Diagnoses: Could It Be Something Other Than Rabbit Syphilis?
The clinical symptoms can often resemble those of myxomatosis, rabbit snuffles, or skin irritation caused by diarrhea, stuck cecotropes, or shaving-related irritation after diarrhea. Because of this, the diagnosis may not always be straightforward. In unclear cases, confirming the pathogen with a laboratory test is recommended (this takes approximately two weeks).
For mild symptoms, it may be reasonable to wait and apply local treatment initially—for example, if the area was cleaned after diarrhea and appears irritated. However, if the inflamed areas do not heal promptly, if no underlying cause for the diarrhea can be found (such as through a fecal exam for parasites or dental X-rays), or if the symptoms keep recurring, a laboratory pathogen test should be performed without delay.
Important: Be sure to visit a veterinarian experienced with rabbits. Many veterinarians are highly knowledgeable about dogs and cats but lack the specialized expertise required for rabbits. This can lead to conditions specific to rabbits, such as rabbit syphilis or dental disorders, being overlooked or improperly treated.
Transmission and Risk of Infection
Especially if left untreated, syphilis often spreads rapidly within a population, affecting multiple rabbits. Infected rabbits can also experience relapses. However, rabbits that have been successfully treated and no longer show symptoms typically do not transmit the disease. The infection is transmitted through mating and contact with rabbit saliva (bites, licking). Young rabbits are usually infected by their mother during the first few days of life. Therefore, syphilis is considered an exclusion disease for breeding. Currently, a vaccine is not available.
Treatment: How Can Syphilis Be Treated?
Standard antibiotics typically do not work, so it is crucial to choose one of the following antibiotics:
- Penicillin (usually Duphamox, 10-20 mg/kg once daily, or Veracin RS 0.1 ml/kg once daily). However, penicillin is often fatal for rabbits if given orally, so it must always be administered via injection. It is also possible to conduct an antibiogram to identify which antibiotic is effective.
- Azithromycin (e.g., Zithromax, 15 to 50 mg/kg per day), given orally (by mouth).
In addition, the affected area is often treated with antibiotic eye drops and ointments.
The penicillin treatment should be supported by eliminating stressors (poor living or feeding conditions, stress within the group, frequent handling, etc.). The immune system can also be supported with (sea) radish, which has antibacterial properties and can be easily mixed with banana (or another favorite food) for administration. It should be introduced gradually (begin with small amounts and increase slowly) and given beyond the healing period, though it is typically effective quite quickly.
Pre- and probiotics can be helpful, as both antibiotics can negatively affect digestion.
For additional support, zinc ointment or coconut oil (available online, in health food stores, or pharmacies) can be used for skin care. This helps reduce inflammation, promotes healing, and kills some of the bacteria. Apply it daily to the affected areas.
Colloidal silver can also be used externally (apply to the affected areas) to combat the pathogen.
Often, supporting the immune system is also necessary.
All of these supportive measures should be used as local treatments alongside penicillin and not as the sole therapy.
Rabbit syphilis before and after treatment with antibiotics and zinc ointment:
Before-and-after photos of rabbit syphilis in a young rabbit.
