Rabbit hemorrhagic disease virus type 2 (RHDV2) is a highly contagious calicivirus that kills 70 to 100 percent of infected rabbits, often with no warning signs. Since 2020 it has become endemic across much of the western and central United States, making vaccination — once optional — now strongly recommended for every pet rabbit. The available vaccines are safe, effective, and require an annual booster.
Last reviewed: May 2026
What RHDV2 Is and Why It Spreads So Fast
RHDV2 is a non-enveloped calicivirus that attacks the liver and clotting system in rabbits. Within 1 to 5 days of infection it causes massive liver necrosis and disseminated intravascular coagulation, killing most rabbits acutely. Unlike the original RHDV1 (which affected only European rabbits), RHDV2 infects every rabbit species — pet European rabbits, wild cottontails, jackrabbits, and hares — which is why it spread across North America so quickly after its 2020 arrival.
The virus is extraordinarily hardy. It survives on surfaces for more than 100 days, withstands freezing and most household disinfectants, and is transmitted by direct contact, contaminated hay, vegetables, bedding, clothing, shoes, insect vectors (flies, fleas, mosquitoes), and even on owners' hands (AEMV Pet Care Guides, 2024).
How RHDV2 Reached the US
RHDV2 first appeared in France in 2010 and spread through Europe, Australia, and Israel over the next decade. It was first confirmed in North American wild rabbits in March 2020 in New Mexico. Within 18 months it was identified in wild populations in Arizona, Colorado, Texas, Utah, Nevada, California, Oregon, Washington, Idaho, and Wyoming, and outbreaks have since been confirmed in additional states. Because it is established in wild lagomorph populations, eradication is no longer possible — exposure risk for pet rabbits is now permanent in many regions.
Why House Rabbits Are at Risk Too
Owners often assume that indoor-only rabbits are safe. They are not. Documented transmission routes for indoor rabbits include hay from fields shared with wild rabbits, fresh greens, leafy vegetables brought in from outdoor gardens, contaminated shoes and clothing carrying the virus inside from grass or trails, and biting insects entering through windows or screens. The virus can persist on hay for more than 90 days.
Available RHDV2 Vaccines in the US
Two RHDV2-specific vaccines are commercially used in the US, both originally approved under USDA emergency-use authorization and now widely available through exotic-savvy veterinarians:
- Filavac VHD K C+V — a French-made inactivated bivalent vaccine covering RHDV1 and RHDV2
- Medgene RHDV2 vaccine — a US-made conditionally licensed inactivated vaccine specifically targeting RHDV2
Both are given subcutaneously in the scruff. Protective immunity typically develops within 7 to 14 days after the first dose. Local reactions at the injection site (a small lump or transient soreness) occur in roughly 5 to 10 percent of rabbits and resolve in 1 to 3 weeks. Serious adverse reactions are uncommon, as noted in Benato et al., 2019, JSAP.
Vaccine Schedule
Standard protocol for an unvaccinated adult pet rabbit:
- First dose at 10 weeks of age or older
- For Filavac: annual booster, with some veterinarians recommending every 6 to 9 months in high-prevalence regions
- For Medgene: initial 2-dose series 3 weeks apart, then annual boosters
- Booster timing within 12 months of the previous dose maintains protective titers
Rabbits with prior gastrointestinal stasis or chronic illness can still safely receive the vaccine — the vaccines do not contain live virus and do not shed.
Cost and Where to Get the Vaccine
The vaccine itself costs $20 to $40, but vet visit fees bring the typical total to $75 to $200 per visit at exotic-friendly clinics. House Rabbit Society chapters and exotic-vet organizations maintain regional clinic lists. Some areas hold pop-up vaccination clinics during outbreaks where the cost can drop to $40 to $60.
Other Disease-Prevention Steps That Still Matter
Vaccination is the most effective single step, but biosecurity reduces residual risk. Recommended practices include changing shoes before entering the rabbit area, washing hands and arms thoroughly before handling, freezing leafy greens for at least 72 hours before feeding if outdoor exposure is possible (freezing inactivates RHDV2), avoiding hay sourced from areas with known wild-rabbit outbreaks, and keeping rabbits indoors during peak fly and mosquito season. Companion rabbits should be vaccinated together to avoid an unvaccinated bondmate acting as a viral reservoir (Oglesbee & Lord, 2010, JEPM).
When to See a Vet
Annual exams are the right time to discuss vaccination. But certain signs warrant immediate attention regardless of vaccine status.
Call your vet today if:
- Vaccine is more than 12 months out of date
- New rabbit added to household without confirmed vaccine history
- Mild lethargy or reduced appetite for 6 to 12 hours
- Injection-site lump that persists more than 4 weeks
- Plans to board, show, or travel with your rabbit
Go to the ER immediately if:
- Sudden death or near-collapse in a previously healthy rabbit
- Bleeding from the nose, mouth, or rectum
- Severe lethargy, seizures, or unresponsiveness
- Difficulty breathing
- Multiple rabbits in the household becoming ill at once
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Frequently Asked Questions
Is the RHDV2 vaccine safe?
Yes. Both Filavac and Medgene are inactivated vaccines — they cannot cause disease. Local reactions (mild swelling or soreness) occur in about 5 to 10 percent of vaccinated rabbits, and serious adverse reactions are uncommon. Tens of thousands of doses have been given in Europe over the past decade and in the US since 2021 without major safety concerns. Pregnant does and very young kits under 10 weeks are typically excluded from vaccination.
How much does the RHDV2 vaccine cost?
Vaccine cost is usually $20 to $40 per dose. The total visit, including exam, runs $75 to $200 at an exotic-savvy clinic. The Medgene protocol requires 2 initial doses 3 weeks apart, so first-year cost is closer to $200 to $400. Annual boosters are a single dose. Group vaccination clinics may charge $40 to $60 per rabbit when available.
Do indoor rabbits really need RHDV2 vaccination?
Yes. Indoor rabbits regularly contract RHDV2 from hay, fresh greens, insects, and owners' shoes and clothing. The virus survives on fabric and surfaces for over 100 days and persists on hay for months. Indoor-only status reduces but does not eliminate exposure risk. Every veterinary organization tracking the outbreak — including the House Rabbit Society and AEMV — recommends vaccinating indoor pet rabbits.
How quickly does protection develop after the first dose?
Protective antibodies develop within 7 to 14 days of the first dose. Until protection is confirmed, keep the rabbit isolated from new hay sources, outdoor exposure, and other rabbits with unknown vaccine history. The Medgene 2-dose primary series provides stronger initial titers than a single dose, which is why it's preferred in active outbreak regions.
What happens if my rabbit catches RHDV2 anyway?
Mortality is 70 to 100 percent. There is no specific antiviral treatment — care is supportive (IV fluids, oxygen, gastroprotectants) and almost all rabbits die within 1 to 5 days. Vaccinated rabbits that contract RHDV2 typically experience much milder illness and have published survival rates above 90 percent. This is the case for the vaccine: not zero risk, but the difference between near-certain death and likely survival.
Can I vaccinate my rabbit myself?
No. RHDV2 vaccines are USDA-restricted to licensed veterinarians in the US. They require cold-chain storage, a proper subcutaneous technique, post-vaccine monitoring, and documentation for travel and registration. DIY vaccination is illegal in most states and risks improper dosing or storage that voids the vaccine's protection.
Can the vaccine be given alongside other vaccines or treatments?
Yes, in most cases. The RHDV2 vaccine can typically be combined with a Pasteurella vaccine (where available) or given during a routine wellness exam. Allow at least 2 weeks between RHDV2 and any unrelated surgical procedure, and avoid giving it during active illness. Always tell your vet about any current medications.
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