RHDV

What is RHDV?

Rabbit Hemorrhagic Disease (RHDV) is a highly contagious and fatal calcivirus. It affects both domestic and wild rabbits. RHDV2 is a new strain of RHDV that is more prevalent strain. You can find more information on RHDV and symptoms here: https://rabbit.org/what-is-rabbit-hemorrhagic-disease/

  • The incubation period for RHDV1 is 2-10 days, and RHDV2 is 3-9 days.
  • The death rate of rabbits exposed to this virus is very high, between 40-100% for RHDV1 and 5-70%+ for RHDV2. Rabbits who survive may shed the virus and be infectious to other rabbits for at least 42 days, perhaps longer.
  • Some rabbits may have few to no symptoms of RHDV2 (subclinical), but may shed virus for up to 2 months.
  • RHDV causes necrotizing hepatitis, and may cause necrosis of the spleen. There may be internal or externally visible bleeding. Death occurs from liver failure or hemorrhage due to an impairment in the blood’s ability to clot.
  • Rabbit calicivirus is a very hardy virus, remaining viable in the environment for 105 days at 68F on fabric – it remains stable for 105 days at room temperature – and for 225 days at 39F. It is not killed by freezing. It survives heat of 122F for one hour.
  • There is no known cure for RHDV.
  • RHDV2 treatment is supportive care in isolation. There are currently no known effective anti-viral drugs or other treatments available.

(Source: https://rabbit.org/rhdv)

 

How RHDV is Spread

RHDV is highly contagious. It can be spread by:

  • Contact of a rabbit with inanimate objects contaminated by the virus (i.e., fomites). These objects include clothing, shoes, and car and truck tires.
  • Direct contact of a rabbit with an infected rabbit or the urine or feces of an infected rabbit.
  • Contact with rabbit products such as fur, meat or wool from infected rabbits.
  • Insects (including flies, fleas, and mosquitoes), birds, rodents, predators, and other pets (cats and dogs) are known to spread the virus by acting as indirect hosts or fomites. They can transport the virus from an infected rabbit to a healthy rabbit.
  • Humans can spread the virus to their rabbits if they have been in contact with infected rabbits or in contact with objects contaminated by the virus, including feces from an infected rabbit.
  • Ingesting virus-contaminated food or water.

 (Source: https://rabbit.org/rhdv)

 

RHDV Symptoms

Symptoms of RHDV in domesticated rabbits include, but are not limited to:

  • Inappetence, or loss of appetite
  • Lethargy, or lack of energy
  • Fever of 104F or higher
  • Seizures, weakness, wobbliness and other neurological signs
  • Jaundice, or yellowing of the skin and mucosal membranes (most noticeably in the ears)
  • Bleeding from nose, mouth, genital openings or rectum
  • Difficulty breathing
  • Sudden death

 (Source: https://rabbit.org/what-is-rabbit-hemorrhagic-disease/)

Maintaining Quarantine in Your Home

The vaccine is the best way to protect your rabbit against RHDV. Even once your rabbit is vaccinated, it is still best practice to reduce the risk of bringing RHDV into your home through maintaining quarantine conditions.

Shoes

Shoes should either be disinfected before coming in the home, especially if you have been in an area where rabbits may be (parks, trails etc). Alternatively, leave shoes outside of the home entirely, ensuring to not step on non-quarantined areas with your feet/socks.

Clothes

Dirty clothes – from a hike or other outdoor activities, should be run through a decontamination 1/2 capacity wash cycle before any contact with your home or rabbit. Most washing machines have a hot cycle that reaches a minimum of 130 degrees fahrenheit. Running potentially contaminated clothes through a hot cycle for at least one hour at above 122 degrees fahrenheit is required to decontaminate. Please check your machine’s manufacturers documents to confirm the specs for your machine. If possible, use 1/2 cup of undiluted bleach in the wash, and dry on high heat.

Hands and Exposed Skin

Washing your hands or any parts of your skin that have been potentially exposed with proper skin safe disinfectants should be done prior to touching any surfaces in your home or interacting with your rabbit. If disinfectants can’t be used, do a double wash with soap for at least 2 minutes each time.

New Objects

Any new objects brought into the home should be allowed to either quarantine for at least 4 months, or be disinfected.

Food

Veggies should be sourced from areas that do not have current outbreak, or grown at home in a controlled environment. Thoroughly wash produce for at least 2 minutes.

Confirm with your hay provider what precautions they take to protect against RHDV. Companies like Oxbow have public statements on how they are keeping hay and rabbits safe: https://www.oxbowanimalhealth.com/blog/rhdv2-what-oxbow-is-doing-to-keep-your-pets-safe/

Do not feed any found or foraged grasses, greens, branches etc.

Dogs/Outdoor Pets

Animals that have exposure to the outdoors can potentially come into contact with RHDV and bring it into the home. Until the vaccine is available, reducing potential contamination risks is the best option, including avoiding going to parks/trails where wild rabbits live, having your dog wear non-porous feet coverings on walks that are removed before returning home, etc. Alternatively, keeping your rabbit(s) quarantined to a specific room or rooms until a vaccine is available is another option in mixed animal homes.

 

Bringing Home a New Rabbit

If a new rabbit is brought into your home, the recommendation is to quarantine them for 14 days away from your other rabbits to ensure the safety of all rabbits involved. During the 14 days, they should be housed in a different room, and there should be no sharing of blankets, litter boxes, food/water dishes, toys, stuffies etc. Any parts of you or your clothes that come into contact with the new rabbit should be properly decontaminated after each interaction. These safety protocols should be in place until the quarantine period is over.

 

Disinfection

For your disinfectant to be optimally effective, mechanically remove surface debris (fur, feces, hay) completely before applying product. Disinfectant labeled to be effective for feline calicivirus should be used, following label instructions for contact time for feline calicivirus.

  • Accelerated hydrogen peroxide (e.g., Rescue)
  • Potassium peroxymonosulfate (e.g., Trifectant or Virkon S)
  • Bleach 1:10 dilution = 1.5c bleach (12oz) in 1 gallon water.
    • Surfaces should be thoroughly cleaned first as organic material deactivates bleach.
    • Check the label on the bleach to make sure it is intended for disinfection, and not expired
    • Never mix bleach with other cleaning products
    • Animals must be removed from the area when bleach is used
    • Wear gloves when handling bleach, and use in a well-ventilated area
    • Once diluted, bleach loses efficacy after 24 hours
    • Wet contact time must be maintained on the surface for at least 10 minutes
    • Following disinfection, bleach should be rinsed off and surface dried before animal contact

 

Keeping Your Bun Safe Outdoors

The safest option is to keep your bun inside in quarantine conditions, and only take them outside in a carrier when going to the vet, for nail trims etc. However if you do choose to bring your rabbit outdoors, it is recommended to take precautions to minimize their exposure risk to RHDV. This includes using tarps/blankets etc. to cover the grass/ground in the area they will be, using an xpen or similar enclosure to keep them contained in the covered area where they are unable to touch the grass, not stepping on the blankets that they are using, and cleaning the blankets etc. in a decontamination wash cycle after use. All it takes is a rabbit, either wild or domestic, that is shedding the virus to have touched the grass for your rabbit to be exposed to the virus, so extreme precaution should be taken.

 

The RHDV Vaccine

Currently, the vaccine is available to some clinics in Ontario. The vaccine is regulated by the government, and if your vet has not ordered the vaccine the best way to encourage getting the vaccine into Ontario veterinary clinics is by requesting it directly from your vet. Either speak to your vet, or have reception relay the message to your vet directly for you.

Even once your rabbit is vaccinated, best practice is to maintain quarantine conditions in your home, because like any vaccine, it is not 100% effective. The vaccine can help diminish the symptoms if a rabbit contracts the virus, though some cases of vaccinated rabbits still died of RHDV (though a very small percent). Most rabbits who are vaccinated would show no symptoms if exposed.

The virus has a very high death rate once contracted in unvaccinated rabbits and there is no cure. 

You can find more information on RHDV here: https://rabbit.org/rhdv/