Sexually Transmitted Bacterial Infections in Rabbits

Treponematosis, or rabbit syphilis, is a sexually transmitted bacterial disease caused by the spirochete Treponema paraluis-cuniculi. This disease is known to affect both males and females, and can be passed between rabbits during mating or from the milk of a doe to her kits. This can cause skin crusting of the genital organs, eyelids, and nostrils, as well as abortion of kits in pregnant does.

It is important to note that this disease is not zoonotic, therefore cannot be passed from rabbits to humans or other species. Despite this, rabbit syphilis is highly infectious between rabbits and it is vital that affected animals are treated promptly to prevent further spread of the condition.

The most commonly seen symptoms in rabbits are raw, painful lesions to the skin of the genital area and perineum as well as the face, particularly the eyelids, muco-cutaneous junction on the lips and nostrils. In some cases, lesions may also form under the chin. These lesions lead to heavy crusting that may bleed and weep pus-like exudate.  As this disease affects the perineal area it is important to differentiate between treponematosis and urine scalding. 

Atypical forms of this disease are also seen, where the lesions affect only the face rather than the genital area, therefore this should be taken into account by your veterinarian when making a differential diagnosis.

• Lesions on the face
• Lesions in the genital area
• Pus
• Crusting of sores
• Soreness from urine scalding

This disease is caused by the spirochete Treponema paraluis-cuniculi. This can be spread through sexual intercourse, through a doe’s milk to their young while nursing, or to young at birth. Although the incubation period of the disease is considered to be 3 to 16 weeks long, this disease can remain dormant for many years, causing no clinical signs. It is often following a stressful event such as change in environment, introduction of a new hutch mate, or illness that symptoms begin to present.

If you notice symptoms of a sexually transmitted bacterial disease in your pet contact your veterinarian to schedule an appointment for your veterinarian to perform a full physical examination on your pet. They will discuss your pet’s clinical history with you and ask if your pet has had contact with other rabbits displaying similar symptoms. 

Your veterinarian may suspect rabbit syphilis due to the symptoms your pet presents with and will be able to diagnose the disease through a sample examined under microscopy which will allow them to visualise the spirochete. Other diagnostic tests your veterinarian may use are serologic tests such as:  

• Venereal Disease Research Laboratory slide test aids in diagnosis by detecting central nervous system involvement, however may show false positives if other conditions such as pregnancy or rheumatoid arthritis are present
• Rapid-plasma regain card test which is able to identify non-specific antibodies in your rabbit’s blood that may indicate infection

Antibiotic Therapy 

The bacterium that causes this condition is sensitive to penicillin, therefore your veterinarian will provide systemic antibiotic therapy for your pet. Syphilis is the only illness that requires penicillin administration in rabbits, and must be given via subcutaneous injection due to the risk of enterotoxemia if given orally. Systemic antibiotic therapy may be given in either of these methods:

• Benzathine penicillin - at the rate of 42,000 IU/kg through subcutaneous injection at weekly intervals for a period of three weeks to five weeks
• Procaine penicillin – at the rate of 60,000 IU/kg through subcutaneous injection at daily intervals for seven days

Analgesia 

If your pet is in discomfort due to the lesions your veterinarian may give systemic analgesia for your pet to provide pain relief in the form of either NSAIDS or opiates. It is important to provide adequate pain relief in rabbits as pain is a major cause of anorexia in rabbits.

Diet 

Due to the risks of gastric stasis, hepatic lipidosis and intestinal ileus caused by anorexia in rabbits, it is vital that your pet eats during his illness. Encourage your pet to eat by providing favourite foods along with fresh water, hay and appetite stimulants such as parsley, carrot tops and kale. If your pet is still refusing food, syringe feeding may be necessary. Your veterinarian may choose to give pellets moistened with water, pureed vegetables or banana.

Syphilis in rabbits is treatable through antibiotic therapy, following the treatment lesions can be expected to heal from 10-14 days. During your pet’s recovery it is vital to provide close monitoring of food intake. In order to prevent re-infection, it is vital rabbits are not bred with until all lesions are healed and other hutch mates are also treated for the disease even if asymptomatic.