Rabbit Hemorrhagic Disease

Rabbit Hemorrhagic Disease (RHD) is a highly contagious and often fatal viral disease that affects both domestic and wild rabbits. It is caused by Rabbit Hemorrhagic Disease Virus (RHDV).

The virus spreads very easily through direct contact between rabbits, contact with bodily fluids such as urine, feces, or nasal secretions, and through contaminated objects including food bowls, bedding, cages, clothing, shoes, and hands. Insects such as flies can also spread the virus.

RHDV2, the currently circulating strain in the United States, is especially concerning because it is very hardy in the environment and can survive for prolonged periods of time. The exact length of survival is unknown. Rabbits that are exposed and survive may continue to carry and spread the virus.

Clinical Signs

Some rabbits show no warning signs and may die suddenly. When signs are present, they may include:

• Fever
• Lethargy or weakness
• Loss of appetite
• Difficulty breathing
• Nasal discharge
• Seizures
• Sudden death

The virus causes severe liver damage, internal bleeding, and rapid organ failure. Mortality rates are extremely high and may reach 70 to 100 percent.

Virus Strains

There are two major strains of rabbit hemorrhagic disease virus:

• RHDV1
• RHDV2

RHDV2 is the newer strain and can affect a wider range of rabbits, including young rabbits. Some infected rabbits may develop a more chronic or milder illness, but many still experience severe disease or death.

Treatment and Prevention

There is no cure or specific treatment for rabbit hemorrhagic disease. Supportive care is often unsuccessful due to how rapidly the disease progresses.

Prevention is critical and includes:

• Strict biosecurity
• Avoiding contact with wild rabbits
• Quarantining new rabbits
• Proper cleaning and disinfection
• Vaccination where available

Rabbit hemorrhagic disease is a reportable disease in many regions, meaning suspected cases must be reported to state or federal authorities.

Vaccination Information

An experimental Rabbit Hemorrhagic Disease Virus Type 2 (RHDV2) vaccine manufactured by MedGene has received emergency use authorization from the USDA.

This vaccine is currently approved for use in New Hampshire for one year.

Veterinarians administering the vaccine are required to report any adverse reactions to both the New Hampshire State Veterinarian and the MedGene company.

Vaccinated rabbits must have an individual form of identification, such as a microchip or tattoo.

The House Rabbit Society in MA is also vaccinating rabbits.

Human Health Risk

Rabbit hemorrhagic disease does not pose a known risk to humans. However, it can have devastating consequences for pet rabbits, wild rabbit populations, and ecosystems where rabbits play an important role.

Reporting Suspected Cases

If Rabbit Hemorrhagic Disease Virus Type 2 is suspected:

• Immediately quarantine the affected rabbit or rabbits
• Contact your veterinarian right away
• Contact your state animal health officials

Veterinarians and owners may also contact:

USDA APHIS Veterinary Services — National Center for Animal Health Emergency Management

1-800-940-6524 (available 24 hours a day)

In New Hampshire, the State Veterinarian’s office can be reached at: 603-271-2404

Cleaning and Disinfection for Rabbit Hemorrhagic Disease Virus

Rabbit Hemorrhagic Disease Virus is extremely resistant in the environment. Thorough cleaning and proper disinfection are essential to reduce spread and risk of exposure.

Environmental Persistence

RHDV can survive for extended periods outside the body. Under certain conditions, it may persist for up to three months on fabrics and within contaminated organic material.

The virus is shed in urine, feces, and respiratory secretions. Bedding, cages, food, water bowls, and surrounding surfaces can all become sources of infection. Insects, birds, rodents, and scavengers may also mechanically spread the virus.

Effective Disinfectants

The following disinfectants are effective against RHDV when used correctly:

• Household bleach (sodium hypochlorite) diluted to a 10 percent solution, made by mixing one part bleach with nine parts water
• Potassium peroxymonosulfate products such as Virkon S at a 1 percent solution with a 10-minute contact time
• Accelerated hydrogen peroxide products such as Rescue with a 5-minute contact time

Always follow manufacturer instructions for dilution, contact time, and safety.

Cleaning and Disinfection Steps

Step 1: Pre-cleaning

Remove all organic material such as bedding, feces, fur, and food debris by sweeping, brushing, or scraping.

Dispose of contaminated materials safely. Options include deep burial where permitted, or double-bagging in plastic bags, disinfecting the outer bag, and disposing of it at a licensed landfill.

Step 2: Washing

Wash surfaces, cages, bowls, and equipment thoroughly with soap and potable water. Rinse well and allow to dry.

Step 3: Disinfection

Apply the chosen disinfectant at the correct dilution. Ensure the surface remains wet for the full required contact time:

• Five minutes for diluted bleach or accelerated hydrogen peroxide
• Ten minutes for Virkon S

After disinfection, rinse with potable water and allow items to dry completely before reuse.

Fallow Period

After cleaning and disinfection, a fallow period is recommended during which no rabbits are introduced to the area. The exact duration should be determined by the State Animal Health Official.

When guidance is unavailable or cleaning is difficult, a minimum fallow period of 90 days is recommended.

Safety Precautions

When cleaning and disinfecting:

• Wear gloves and eye protection
• Ensure good ventilation
• Never mix disinfectants
• Follow all label instructions carefully

Additional Guidance

For detailed and up-to-date information, refer to USDA guidance on cleaning and disinfection of RHDV-contaminated premises or call our office at (603) 882-0494 for assistance.