Rabbit Hemorrhagic Disease Virus 2
Rabbit Viral Hemorrhagic Disease is caused by a Calicivirus. Though multiple types of this virus have been identified, the serotype that has been seen in the most recent outbreaks here in the United States involves Rabbit Hemorrhagic Disease Virus serotype 2 (RHDV2). RHDV2 is a non-enveloped, single stranded RNA calicivirus that targets the liver and causes destruction of the cells within the liver leading to severe liver damage and dysfunction as well as problems with the animal’s ability to clot his/her blood. Clotting disorders lead to the bruising and bleeding that can be seen within the whites of the eyes, the eye lids, and nostrils as the disease progresses. This strain of RHDV affects both our beloved domestic house rabbits as well as some of the wild rabbit population. In general, a rabbit exposed to the virus can show signs within 1 to 5 days. If a rabbit survives, he/she may not show any signs of the virus and continue to shed the active particles for up to 40 days. Due to the structure of the virus, it is sturdy and can remain in the environment for over 100 days in the right conditions and has been shown to survive over 90 days in the carcass of a dead animal. It can also survive freezing temperatures and the thawing process. There have been several disinfectants that prove effective. These require scrubbing in order to break through any dirt and debris and allow the disinfectant to access the virus. Effective disinfectants include dilute bleach (1-part bleach to 10 parts water), Virkon, Rescue, parvasol, and Peroxiguard. Currently, there is no known direct treatment for this disease so prevention is key. Supportive care is recommended as some will recover.
A rabbit can become exposed to the virus through:
- humans, clothing, and equipment that have come in contact with infected animals
- direct contact with infected live rabbits as well as dead rabbit meat and fur.
- insects’ flies, fleas, and mosquitoes
- rodent exposure as well as through the feces of predatory birds and mammals who have ingested an infected rabbit.
- when directly coming into contact with bodily fluids of an infected rabbit (urine, feces, respiratory secretions, etc.)
Clinical signs for RHVD2 can include:
- quiet, decreased energy
- decreased or loss of appetite
- incoordination, abnormal walking, seizure-like activity
- increased respiratory effort and rate
- bloody nasal discharge
- bleeding within the eyelid and whites of the eyes
- yellowing of the skin, ears, and whites of the eyes
- weight loss
- GI signs (Stasis, diarrhea, etc.)
Currently, there is no known treatment for this disease other than supportive care. It is best to focus on prevention. Ways to prevent this disease can include:
- Vaccines, where immunity has been shown within 7-10 days
- House your rabbit indoors to prevent exposure to wildlife and insects
- Avoiding contact with other people’s rabbits or wash-up and change your shoes and clothes once returning home if visiting places where you might have been exposed to other rabbits (feed stores, rescues, humane society, fair grounds, etc.)
- Wash your hands and do not share equipment between rabbits within your household if they are housed separately
- Minimize insects entering into your home.
- Quarantine any new incoming rabbits away from a population for at least 30 to 40 days