Syphilis in rabbits, sometimes referred to as Vent disease, is caused by the bacteria known as Treponema cuniculi. This serious disease is many times mistaken for simple hutch burn or vice versa. This form of syphilis is not the same that humans can contract but the bacterium that causes the disease in rabbits and humans are related.
Rabbit syphilis can be spread between rabbits by sexual contact or breeding. The more a rabbit is bred, the more chance it has at becoming infected with syphilis. Normal contact between rabbits can also spread the disease and does can pass syphilis onto their kits. Rabbit syphilis is not zoonotic and cannot be transmitted between humans and rabbits.
The symptoms of syphilis in rabbits are painfully obvious and can be found in both bucks and does. The genital area will develop sores that become crusty. This can spread to the face area including the nose, mouth, eyes, and chin when the rabbit grooms the genital region. The area will first appear reddened and then begin to swell. The lesions will form scabs with 15 percent of infected rabbits then having the syphilis spread to the face area. The genitals will be painful and the rabbit generally refuses to breed.
A rabbit that is suspected of having syphilis should be quarantined from other rabbits and be seen by an experienced rabbit veterinarian. The vet should do more than a simple external examination to rule out hutch burn. The bacterium that causes syphilis will need to be confirmed through a simple scraping taken from the area.
Rabbit syphilis is completely treatable with proper antibiotics. Topical ointments may relieve the pain and soreness but they will not kill the bacteria that caused the disease. Rabbit owners should become knowledgeable in what antibiotics are harmful to rabbits and which are safe. The most common antibiotic used for treating Vent disease is Benzathine penicillin with treatment typically lasting three weeks.
When a rabbit is on antibiotics, owners should watch their rabbit's eating, drinking, and bathroom habits. Allow plenty of fresh timothy hay to aid in digestion while the rabbit is on the medication. Diarrhea is a common side effect in rabbits on antibiotic treatments which can lead to enteritis (inflammation or infection of the intestines). Notify the veterinarian immediately if the rabbit stops eating or develops diarrhea.
Preventative measures can be taken that can help avoid a rabbit from developing syphilis as well as many other diseases. Rabbits should be quarantined before introducing to other rabbits or into a breeding program. Always examine a rabbit thoroughly before breeding and do not breed rabbits that appear sick or show any signs of illness. A rabbitry that exercises good husbandry practices is less likely to have outbreaks of bacteria that cause disease.
THE RABBIT HANDBOOK, by Dr. Karen Gendron, copyright 2000.