RHDV2

RHDV2, or Rabbit Hemorrhagic Disease Virus type 2, is the strain of rabbit hemorrhagic disease currently spreading across North America and it represents the single greatest viral threat to domestic rabbits today. Unlike the original RHDV strain that primarily affected European rabbits over the age of about eight weeks, RHDV2 kills rabbits of all ages, all breeds, and even crosses into wild species like cottontails and jackrabbits. If you keep rabbits and you are not already aware of this disease, please take this seriously.

RHDV2 was first identified in France in 2010 and has since spread to countries across Europe, Africa, Australia, and North America. It arrived in the southwestern United States around 2020 and has been confirmed in wild and domestic rabbit populations across a steadily growing number of states and Canadian provinces. The virus spreads easily, kills quickly, and persists in the environment for extended periods, making it a formidable threat that is difficult to contain once established in an area.

The severity of this disease is hard to overstate. Mortality rates in unvaccinated rabbits can reach 90 percent or higher. Many rabbits die within 12 to 36 hours of infection, often with no symptoms at all. Owners find their apparently healthy rabbit dead with no prior indication that anything was wrong. For those rabbits that do show symptoms before death, the progression from first signs to death can be measured in hours rather than days.

Rabbits are already masters at hiding illness due to their prey animal instincts, and RHDV2 exploits this perfectly. The disease often kills before a rabbit shows any detectable signs, meaning that even the most attentive owners cannot reliably catch it in time for intervention. There is no cure, no specific antiviral treatment, and supportive care rarely changes the outcome once symptoms appear. Prevention through vaccination and biosecurity is the only practical defense.

This article covers how RHDV2 spreads, what it does to rabbits, what symptoms to watch for in the rare cases where they appear, what your vet can and cannot do, and most importantly how to protect your rabbits through vaccination and common-sense biosecurity measures.

RHDV2 is caused by a calicivirus that is closely related to but genetically distinct from the original RHDV strain. This matters because immunity to one strain does not necessarily protect against the other, which is why specific RHDV2 vaccines were developed. The virus targets the liver primarily, causing massive organ failure and internal hemorrhaging that leads to rapid death.

Transmission happens through multiple routes, and this is where things get genuinely alarming for rabbit owners. Direct contact with an infected rabbit is the most obvious pathway, but it is far from the only one. The virus sheds in enormous quantities through the droppings, urine, nasal secretions, and blood of infected rabbits. It survives on surfaces, in soil, on vegetation, and in dried biological material for weeks to months depending on conditions. It resists many common disinfectants and can tolerate temperature extremes that would inactivate most viruses.

You do not need to bring your rabbit into contact with another rabbit for exposure to occur. The virus can ride into your home on your shoes after you walk through a park, field, or even a parking lot where infected wild rabbits have been. It can arrive on hay or straw harvested from fields where wild rabbits graze. Insects, particularly flies and mosquitoes, can carry the virus mechanically on their bodies and deposit it in your rabbit's living area. Predators and scavengers that feed on infected carcasses can spread the virus across wide geographic areas.

Every rabbit that is unvaccinated is at risk regardless of whether they live indoors or outdoors. Indoor rabbits face lower but not zero exposure risk because of the many indirect transmission routes described above. Outdoor rabbits, particularly those in areas with confirmed wild rabbit die-offs, face extremely high risk. Multi-rabbit households face the additional danger that once one rabbit is infected, the virus can sweep through the entire group before anyone realizes what is happening.

Rabbits who attend shows, board at facilities, or travel for breeding face heightened risk due to potential contact with animals from different regions with unknown vaccination histories. Even well-managed show environments can become transmission points if a single infected rabbit passes through.

Age is no longer a protective factor with RHDV2. The original strain tended to spare very young rabbits, but RHDV2 kills kits as young as a few weeks old. Breed provides no protection either - every domestic rabbit breed is susceptible, as are wild cottontails, jackrabbits, hares, and pikas. Pregnant and nursing does are particularly vulnerable, and infection typically results in loss of the entire litter along with the doe.

The most common presentation of RHDV2 is sudden death with no prior symptoms. That single sentence captures why this disease is so devastating and why prevention is the only meaningful strategy. Many owners discover their rabbit has died overnight or during a normal part of the day, with no preceding illness, behavior change, or appetite loss. Post-mortem examination may reveal blood at the nose or mouth, but often there are no external signs at all.

In cases where symptoms do develop before death, the clinical course is usually measured in hours. Early signs include sudden loss of appetite, lethargy, and a reluctance to move. Your rabbit may sit in a hunched posture and refuse food, including treats they would normally jump at. These signs can easily be mistaken for GI stasis or another common condition, which is one of the heartbreaking aspects of RHDV2 - by the time you realize this is not a simple belly ache, the disease has progressed beyond help.

As the virus attacks the liver and causes widespread hemorrhaging, more specific symptoms may appear. Fever is common in the early stages, though many rabbit owners do not have the equipment or experience to detect it. Difficulty breathing or rapid shallow breathing indicates that the disease is affecting the respiratory system. Neurological signs including seizures, disorientation, and sudden collapse can occur as the brain is affected by toxins the failing liver can no longer process.

Bloody discharge from the nose or mouth is the hallmark sign of hemorrhagic disease, but not every rabbit with RHDV2 shows this. When it does appear, it indicates severe internal hemorrhaging and the outcome at this point is almost always fatal. Some rabbits develop jaundice, visible as yellowing of the inner ears or the whites of the eyes, reflecting the liver damage that the virus causes.

In a multi-rabbit household, the death of one rabbit followed by illness or death of others within a few days is a strong indicator of RHDV2 and should be treated as a presumed outbreak. Isolate any surviving rabbits immediately, contact your vet, and report the situation to your state veterinarian, as RHDV2 is a reportable disease in most jurisdictions. It is also worth noting that some rabbits can become subclinically infected, meaning they carry and shed the virus without ever showing obvious symptoms themselves. These carrier rabbits can unknowingly spread the disease to unvaccinated housemates, which is another reason vaccination of every rabbit in a household matters.

Definitive diagnosis of RHDV2 typically happens after death through post-mortem examination and laboratory testing. The characteristic finding is a swollen, discolored liver with widespread hemorrhaging throughout the body, particularly in the lungs, spleen, and kidneys. Laboratory confirmation uses PCR testing on liver tissue, blood, or other samples to identify the specific virus.

In a living rabbit showing suspicious symptoms, your vet may submit blood samples for PCR testing, but the rapid progression of the disease means results often arrive after the rabbit has already died. Blood work in an acutely ill rabbit may show elevated liver enzymes, low platelet counts, and signs of disseminated intravascular coagulation, a condition where the blood clotting system fails and causes both clotting and bleeding simultaneously.

There is no antiviral treatment for RHDV2. Once a rabbit is infected, the only option is aggressive supportive care, and even that rarely changes the outcome for severely affected rabbits. Supportive care includes intravenous or subcutaneous fluids to maintain hydration, thermal support to manage body temperature, syringe feeding for rabbits still willing to swallow, pain management, and medications to address specific symptoms like seizures.

Some rabbits do survive RHDV2 infection, particularly those with the subacute form where progression is slower and less overwhelming. Survivors require weeks of intensive supportive care and may suffer lasting liver damage that affects their health for the rest of their lives. They can also shed the virus for a period after recovery, posing a risk to other unvaccinated rabbits. Recovery rabbits need ongoing liver function monitoring and may require dietary adjustments to support their compromised organ. Survival rates even with excellent veterinary care remain very low for the acute and peracute forms.

The real treatment for RHDV2 is prevention through vaccination. Vaccines are available through rabbit-savvy veterinarians and have been shown to provide strong protection. The vaccination protocol typically involves an initial dose with a booster several weeks later, followed by annual revaccination. Your vet will determine the specific schedule based on the vaccine product available and your rabbit's individual health status.

If your rabbit is diagnosed with or suspected of having RHDV2, your vet is required to report the case to state and federal animal health authorities. This is not something to be alarmed about - it is a public health measure designed to track the spread of the virus and protect other rabbits in your community. Reporting also helps wildlife agencies monitor the impact on wild rabbit populations, which is important for understanding how the virus is moving through the broader ecosystem. Your vet will handle the reporting process, and it does not result in any punitive action against you or your rabbits.

Prevention of RHDV2 rests on two pillars - vaccination and biosecurity - and both matter. Vaccination is by far the most important step. Contact a rabbit-savvy veterinarian and get your rabbits vaccinated as soon as possible. Do not wait for confirmed cases in your area, because by the time a case is reported, the virus has likely been circulating locally for some time. The vaccine is safe, effective, and represents the single best investment you can make in your rabbit's continued health.

Biosecurity measures provide an additional layer of protection that complements vaccination. Change your shoes or use dedicated footwear when entering your rabbit area, especially if you have been outdoors in places where wild rabbits may be present. Wash your hands thoroughly before handling your rabbits after being at pet stores, farm supply shops, or outdoor areas. If you source hay from local farms rather than sealed commercial bags, consider that fields where hay is cut may be frequented by wild rabbits whose droppings could contaminate the product.

Insect control is an underappreciated component of RHDV2 prevention. Flies and mosquitoes can carry the virus mechanically on their bodies, so screening outdoor enclosures and managing insect populations around your rabbit area helps reduce one transmission pathway. This is especially important during warmer months when insect activity peaks.

If you bring new rabbits into your home, quarantine them for a minimum of two weeks in a separate area before allowing any contact with your existing rabbits. Ideally, new rabbits should be fully vaccinated before they join your group. Use separate food dishes, water bottles, and cleaning supplies for quarantined rabbits, and wash your hands between handling them and your established rabbits.

Stay informed about RHDV2 cases in your region through your state veterinarian's office, the House Rabbit Society, and local rabbit rescue organizations. Knowing your local risk level helps you calibrate your biosecurity efforts appropriately. Even in areas without confirmed cases, maintaining basic precautions and keeping vaccinations current gives you the best chance of keeping your rabbits safe from a disease that is still actively spreading.

If your rabbits are not vaccinated against RHDV2, contact a rabbit-savvy veterinarian today. Not next week, not when you get around to it - today. This disease is present in wild rabbit populations across much of North America, and your rabbits have zero protection without the vaccine. Call your vet and specifically ask about the RHDV2 vaccine. If your current vet does not carry it or is not experienced with rabbits, find one who is.

If you find a rabbit dead unexpectedly with no prior illness, especially if there is blood at the nose or mouth, contact your veterinarian immediately and let them know you are concerned about possible RHDV2. Do not handle the deceased rabbit without gloves, and keep any surviving rabbits isolated from the area where the death occurred. Your vet will advise on testing and reporting to state animal health authorities.

If a living rabbit shows sudden severe lethargy, complete appetite loss, difficulty breathing, or any bloody discharge, treat this as an emergency regardless of whether you suspect RHDV2 specifically. These symptoms demand immediate veterinary attention. Let your vet know on the phone that you are coming so they can prepare and take appropriate infection control precautions.

Finding a rabbit-savvy vet before an emergency happens is one of the most important things you can do as a rabbit owner. The House Rabbit Society maintains a veterinarian directory, and local rabbit rescue groups often have trusted recommendations. A vet who understands rabbit medicine will not only provide appropriate vaccination but will also be your best resource if your rabbit ever becomes seriously ill. Do not wait until you have an emergency to figure out where to go.