RHDV2—Rabbit Hemorrhagic Disease Virus type 2—is a highly contagious calicivirus that kills domestic and wild rabbits, often within hours and sometimes with almost no warning. It has spread across much of the United States since 2020 and is considered endemic in many counties. You should care because there is no reliable home treatment once infection hits; prevention through biosecurity, limiting contact with wild rabbits and contaminated surfaces, and vaccination where your vet recommends it is the practical playbook.
If you have been refreshing outbreak maps at midnight, you are not overreacting. This one is scary, fast, and real—but not hopeless. A USDA-authorized RHDV2 vaccine is available through veterinarians in many states, and knowing your county’s status changes what you do at home today.
Symptoms, spread, vaccines, local risk maps, hay safety, and what we watch in Northern California sourcing—all of that is here. For how disease prevention fits into overall rabbit wellness, see our pet rabbit health and lifespan guide.
What Is RHDV2 and Why Should Rabbit Owners Care?
Rabbit Hemorrhagic Disease (RHDV2) attacks the liver and blood-clotting system. Infected rabbits may show fever, lethargy, or bleeding—but many die so quickly owners find a healthy-looking bun gone with no obvious signs. That speed is why sudden death in an otherwise normal rabbit should be reported to a vet as a possible RHDV case.
Unlike older RHDV1 strains that mainly hit wild populations in North America, RHDV2 infects both wild and pet rabbits here. It does not infect humans, but people can carry the virus on shoes, clothes, and hands after visiting outbreak areas or handling infected materials.
A safe and effective RHDV2 vaccine is available in the U.S. through licensed veterinarians. The House Rabbit Society strongly recommends vaccination for pet rabbits in at-risk areas—call your rabbit-savvy vet and ask if that includes yours.
What Are the Symptoms of RHDV2 in Pet Rabbits?
Some infected rabbits show nothing at all before they die—the most common pattern with the North American strain. When signs appear, they may include:
Loss of appetite
Lethargy
High fever
Seizures
Bleeding from the nose, mouth, or rectum
Difficulty breathing
Sudden death
Rabbitors groups what owners see into three patterns:
Peracute: Found dead within hours of acting normal—most common. Many cases show no external bleeding.
Acute: Lethargy, fever above 104°F, rapid breathing, death within about 12 hours.
Subacute: Milder signs; some rabbits recover and gain immunity.
If your rabbit dies suddenly, tell your vet it could be RHDV2—do not assume “old age” without a conversation. Baseline health habits help you spot when something is off sooner; our article on how to tell if a rabbit is healthy walks through daily checks.
How Does RHDV2 Spread—and Can Humans Carry It?
The USDA describes RHDV2 as hardy: it survives heat and cold better than many viruses and spreads through direct contact, infected urine or blood, carcasses, food, water, and contaminated bedding or hay. Humans are not infected, but we can track it indoors on clothing and footwear after visiting shelters, shows, or outbreak zones.
Survivors can shed virus for weeks—sometimes longer—so “recovered” does not always mean “safe to mingle” without vet guidance.
Is There an RHDV2 Vaccine for Pet Rabbits?
Yes—in countries where RHDV2 is endemic, vaccination is routine. In the U.S., Medgene Labs offers a killed recombinant vaccine under USDA conditional license in dozens of states plus Washington, D.C. It is a two-dose series: second dose 21 days after the first, then boosters per your vet’s schedule.
California’s Department of Food and Agriculture continues to make the vaccine available to licensed veterinarians. Rabbit owners contact their private vet; vets contact Medgene at info@medgenelabs.com for ordering details.
Vaccination is region- and risk-dependent—not every bun in every zip code needs the same schedule. Our companion article when rabbit vaccinations are a must covers timing and vet conversations in more depth. You can also read the House Rabbit Society vaccine summary.
How Do I Check My Rabbit's Local RHDV2 Risk and Vaccine Guidance?
Start with official maps and your state agriculture or wildlife agency—not rumor threads alone.
United States county maps
The USDA RHDV2 county map shows where domestic and wild cases have been confirmed. Domestic and wild detections are tracked separately because patterns differ. The maps below reflect data through late 2024; always check USDA and state pages for current detections.
Domestic rabbit cases by county
Red outline = endemic/stable RHDV2 area. Gray-filled counties = confirmed domestic cases (shade intensity reflects case counts: slate gray for four or more, sky blue for two to three, light blue-gray for one).
Wild rabbit cases by county
Red outline = endemic/stable area. Red-toned fills = wild rabbit detections (Indian red for four or more, light coral for two to three, light pink for one).
Our hay is grown at the top of Northern California—far from most mapped outbreak clusters to date. Distance is not immunity, but it is context when you compare your county to your supplier’s region.
California-specific monitoring
California’s first detection was May 2020 in Riverside County. As of early 2025, CDFA reports RHDV in domestic and/or wild rabbits in 27 California counties—considered endemic in those areas. Recent domestic detections include Santa Cruz, Riverside, San Bernardino, San Diego, Alameda, and Santa Clara counties.
CDFA’s RHD page lists affected counties with dates and separates domestic vs. wild findings. California also quarantines rabbits entering from RHD-affected states unless they carry a Certificate of Veterinary Inspection.
For state-by-state vaccination and biosecurity statements, the community-maintained RHDV2 regulations wiki is a useful starting point—then confirm with your vet. The Rabbit Hemorrhagic Disease News Network on Facebook tracks breaking case reports if you want a community pulse between official updates.
What Is the Difference Between RHDV1 and RHDV2?
RHDV1 appeared in the 1980s and reached the U.S. in the 2000s, mainly affecting wild rabbits. RHDV2 surfaced in France in 2010 and was confirmed in North America in 2018. The critical difference for pet owners: RHDV2 infects both wild and domestic rabbits here.
RHDV1: incubation roughly 2–10 days; death rate in exposed rabbits often 40–100%.
RHDV2: incubation roughly 3–9 days; death rate in exposed rabbits roughly 5–80%.
Survivors can shed virus for at least 42 days. CDFA’s RHDV information sheet includes printable biosecurity tips.
How Long Can RHDV2 Survive in the Environment?
Estimates vary, but the USDA notes dried virus may remain stable about three months while virus in fresh excretions on surfaces typically fades within weeks as viability drops. That is why quarantine periods, shoe changes, and cage sanitation matter after visiting high-risk sites—not just on day one.
Should I Worry About RHDV2 on Hay or Packaged Products?
The risk of your rabbit catching RHDV2 from commercially packaged hay from a trusted producer is very low. For hay to carry live virus, an infected animal would need to pass through the field during a narrow window when conditions keep the virus stable—a rare chain of events.
Reputable growers use harvest and handling practices that reduce contamination risk. Still, biosecurity at home—indoor housing where possible, clean litter routines, hand washing—matters more than panic-buying.
What Is Rabbit Hole Hay Doing About RHDV2?
We monitor CDFA and USDA reporting closely. To date there have been no reported RHDV2 cases in the Northern California regions where we source hay and operate our warehouse. Current inventory is from the 2024–2025 growing season in that area.
USDA guidance suggests dried RHDV2 may remain stable about three months. Given harvest timing relative to recent distant detections, we are confident product on our site and partner marketplaces is not carrying active virus—but we stay vigilant as fields are cut and baled in coming seasons.
We treat RHDV2 like the serious threat it is: watching official channels, following recommended precautions, and sourcing with your small pet’s safety in mind. If county status near our fields changes, we will update this page.
How Can You Protect Your Rabbit from RHDV2?
Work the list that matches your local risk—your vet should help you prioritize:
Ask your rabbit-savvy veterinarian about RHDV2 vaccination, especially in endemic counties.
House rabbits indoors when possible; outdoor hutches increase contact with wild rabbits, flies, and tracked-in soil.
Use predator-safe fencing if they must have outdoor time; supervise and check for disturbances.
Clean litter boxes, dishes, and bedding on a steady schedule.
Wash hands before handling rabbits; change clothes after visiting other rabbits, shelters, or shows.
Avoid bunny playdates and shows during local outbreaks.
Do not touch dead wild rabbits; report multiple carcasses to state wildlife officials.
Keep shelter-only shoes and clothing if you volunteer where cases have occurred.
Consider a no-shoes-indoors policy to limit what rides in from the yard.
None of this makes you the rabbit police—it is the unglamorous stuff that buys time when a county on the map turns red. Sudden appetite loss can signal gut emergencies unrelated to RHDV2 but equally urgent—see GI stasis warning signs if eating slows.
Key Takeaways
RHDV2 is a fast, often fatal calicivirus in pet and wild rabbits; sudden death warrants reporting to a vet.
Check USDA and state maps for your county, then talk to a rabbit-savvy vet about vaccination and biosecurity.
Hay from trusted commercial sources is very low risk; home hygiene and limiting rabbit-to-rabbit contact matter more day to day.
You cannot control every wild rabbit in the neighborhood—but you can control vaccines, indoor housing, and what comes in on your shoes. That is not paranoia; it is the boring work that keeps buns alive when a county flips red on the map.
New to rabbit care and pulling your setup together while you read outbreak news? Our beginner rabbit care guide covers housing, hay, and daily routines in one place.
Comments