Rabbit hemorrhagic disease (RHD) is a highly contagious and often fatal viral infection that affects domestic and wild rabbits. Mortality rates range from 40% to 100% for the classical strain and up to 80% for newer variants, making it one of the deadliest diseases rabbits can contract. The virus attacks the liver and causes massive internal bleeding, and death can occur so rapidly that owners find their rabbit dead with no prior warning signs.
The Virus Behind RHD
RHD is caused by a virus in the Lagovirus genus, part of the Caliciviridae family. There are two main strains you’ll encounter in discussions about the disease: RHDV1 (the classical form, first identified in China in 1984) and RHDV2 (a newer variant that emerged in France around 2010 and has since spread globally, including across the United States).
The two strains differ in important ways. RHDV1 only infects European rabbits and typically spares very young kits under 4 to 8 weeks old. RHDV2 has a broader host range, causing disease in hares as well as rabbits, and it can kill animals as young as 11 days old. The two strains belong to different serotypes, meaning immunity to one provides little or no protection against the other.
RHDV2 was initially considered less lethal than the classical strain, with early studies reporting average mortality around 20% to 30% in experimentally infected rabbits. More recent isolates have been far more deadly, with mortality rates climbing to 80% in some outbreaks. The classical RHDV strain kills 40% to 100% of infected rabbits.
How the Virus Spreads
The virus spreads through nearly every route imaginable. Direct contact between rabbits is the most obvious path, but RHDV also transmits through contaminated food, water, bedding, clothing, shoes, cages, and any other surface that has come in contact with an infected animal. Infected rabbits shed the virus in their urine, feces, and respiratory secretions. Oral transmission is the most common route, though the virus can also enter through the nose or eyes.
Insects play a major role in carrying the disease over long distances. Flies, mosquitoes, and ticks act as mechanical vectors, picking up viral particles from infected rabbits or carcasses and depositing them elsewhere. The virus can remain infectious inside flies for up to nine days, and it takes only a tiny amount of virus delivered to a rabbit’s eye to cause infection. Predators and scavengers that eat infected rabbits can also spread the virus by excreting it in their droppings.
What makes RHDV especially dangerous is its resilience. The virus can survive on surfaces at room temperature for over 100 days. It remains viable in the decaying tissue of dead rabbits for up to 90 days and persists in chilled or frozen rabbit meat for years. It survives freeze-thaw cycles. At around 72°F, it stays infectious for 22 to 35 days on contaminated objects. This environmental toughness means a rabbit can be exposed long after an infected animal has died or been removed from the area.
Signs and Symptoms
RHD progresses in three general patterns, depending on how the individual rabbit responds to infection.
In the most severe form, called peracute disease, rabbits die suddenly with no visible symptoms at all. Owners may find a seemingly healthy rabbit dead in its enclosure. This is often the first indication that the virus is present.
In the acute form, rabbits show signs of illness before death. Fever above 104°F is common, along with rapid breathing, loss of appetite, and lethargy. Severe diarrhea often develops. As the disease progresses, neurological signs appear: rabbits may lie on their sides, paddle their legs, lose coordination, or exhibit frantic behavior sometimes accompanied by squealing. About 20% of infected rabbits develop a bloody, foamy discharge from the nose and occasionally from the vagina. The incubation period for RHDV1 is 1 to 3 days. RHDV2 takes slightly longer, typically 3 to 9 days from exposure to the onset of symptoms.
A subacute form also exists, where rabbits become visibly ill but many survive. These animals show similar symptoms to the acute form but at a less intense level.
How RHD Is Diagnosed
Because sudden death can have many causes in rabbits, laboratory testing is needed to confirm RHD. The gold standard is testing liver tissue, since the virus targets the liver and reaches its highest concentrations there. Veterinary labs analyze samples using a specialized genetic test (RT-PCR) that detects the virus’s genetic material.
When a full carcass isn’t available or is too decomposed for liver collection, labs can also test lung, spleen, ear tissue, or blood absorbed onto filter paper. These alternative samples have made surveillance easier, particularly for wild rabbits found by hikers or wildlife officials where carcass quality is poor due to predation or decay.
Reporting Requirements
RHD is a reportable disease in the United States, meaning any suspected case must be reported to animal health authorities. If you suspect your rabbit has died from RHD, contact your state veterinarian or the USDA’s Area Veterinarian in Charge. After hours and on weekends, the Foreign Animal Disease Hotline is available at 866-536-7593. Internationally, RHD is also tracked by the World Organisation for Animal Health (WOAH), reflecting its significance to global rabbit populations and agriculture.
Vaccination Options
Vaccines are the most effective tool for protecting rabbits against RHD. In the United States, RHDV2 vaccines have been available through emergency use authorization. In Europe, more options exist. Nobivac Myxo-RHD Plus is a widely used combination vaccine that covers myxomatosis and RHD strains, though questions have emerged about its effectiveness against newer, highly virulent RHDV2 variants.
A newer vaccine called YURVAC RHD, produced by the pharmaceutical company Hipra, received specific authorization from the European Medicines Agency for protection against these highly virulent strains. It became available to veterinary practices in late 2024 and early 2025. For rabbits in high-risk settings like rescues and shelters, some veterinary organizations recommend using both vaccines to provide the broadest possible coverage. For individual pet rabbits, the decision depends on local risk and is best made with a veterinarian familiar with the disease’s presence in your area.
Biosecurity and Disinfection
Given how long the virus survives in the environment and how easily it hitches a ride on shoes, clothing, and insects, biosecurity measures are critical for anyone who keeps rabbits. If you live in an area where RHDV2 has been detected, keeping rabbits indoors and using insect screens can reduce exposure. Wash your hands and change clothes before handling your rabbits if you’ve been in contact with other rabbits or visited areas where wild rabbits live. New rabbits should be quarantined before being introduced to existing animals.
If you need to disinfect an area where an infected rabbit has been, the USDA recommends several effective options:
- Household bleach (sodium hypochlorite): Mix half a cup of standard 6% or 8.25% bleach into one gallon of water. Apply to surfaces and allow 5 minutes of contact time before rinsing with cold water and air drying.
- Potassium peroxymonosulfate (sold as Virkon S): Mix one scoop or sachet (about 1.3 ounces of powder) into one gallon of water to achieve a 1% solution. Allow 10 minutes of contact time.
- Accelerated hydrogen peroxide products (such as Rescue): Dilute 8 ounces of concentrate per gallon of water. Wet the surface thoroughly and allow 5 minutes of contact time before wiping and air drying.
All organic material, including hay, bedding, droppings, and fur, must be removed before disinfecting. The chemicals can’t penetrate through debris to reach the virus underneath. Carcasses and contaminated bedding should be disposed of carefully, ideally by incineration or deep burial, to prevent scavengers from spreading the virus further.