Updated on September 16th, 2022 - Several cases of RHDV in Calgary have been confirmed in August and September 2022, while many dead animals have been spotted.
Bunny ownership has gained tremendous popularity in Canada within the last decade. Although official statistics are not available, it is estimated that bunnies are now in third place after dogs and cats as pets in North America.
When I was younger, I remember neighbors breeding rabbits in their backyard, most of them living outside in wooden hutches. Having a bunny as a *pet* back then was a novelty. Nowadays, bunnies often live in sophisticated indoor cages, or are free to roam the house just like cats and dogs. Bunnies have access to specialized veterinary care, and a wide variety of items, food, toys and treats are developed specifically for them. Some bunnies are even Instagram stars!
For the longest time, bunnies and rabbits in Alberta (and the rest of Canada) have been able to live their lives without the fear of severe transmissible and fatal diseases. Unfortunately, with the arrival of the "Rabbit Hemorrhagic Disease Virus" (or RHDV) in North America, this is about to change.
Bunny owners need to be ready for RHDV and RHDV 2.
What are RHDV and RHDV2?
Rabbit Hemorrhagic Disease Virus is a highly contagious and usually fatal disease that affects wild and domesticated rabbits and hares. There are two strains of the virus: RHDV and RHDV2. Confirmed cases of RHDV have been detected in more than 40 countries (including Canada and the USA) since 1984, while the RHDV2 strain emerged a decade ago and has been gradually replacing RHDV as the dominant strain in several countries, including in the USA, Mexico and Canada in 2020-2022.
The virus is known to kill rabbits very quickly and often, with no warning signs or symptoms. RHDV and RHDV2 have very similar incubation periods, from one to 5 days, while bunnies are reported to die between a few hours to a couple of weeks after the initial exposure and/or onset of symptoms.
Unfortunately, most bunnies (90%-100%) will not survive RHDV and RHDV2. Early symptoms will include loss of appetite, difficulty breathing, fever, lethargy and bleeding from nose, mouth and rectum. Ultimately, the virus will cause necrosis of the liver and the spleen, causing organ failure and/or a hemorrhage within only a few days. Bunnies who have been exposed to a confirmed case of RHDV will usually be euthanized. There is no cure or treatment for both RHDV and RHDV2.
The virus does not affect humans and other animal species.
How does RHDV and RHDV2 spread?
Rabbits get infected by exposure to the virus through oral, nasal, respiratory and ocular routes.
The most common way the virus is spreading is via contact with the urine and feces of sick and infected wild and domestic rabbits, while they are shedding virus in the environment. Blood-feeding insects, such as flies, fleas and mosquitoes have also been known to transmit the virus between different animals.
Bunnies can also get sick through human contact, or via contact with objects contaminated by the virus. Because the virus can be picked up outside by humans, dogs and cats, and by items such as clothes, shoes, food, produce and hay, indoor rabbits are also at risk.
RHD is a very hardy virus that will remain viable in the environment for several months, surviving freeze/thaw cycles and high temperatures. It can remain undetected in the environment for a long time. Unfortunately, by the time an infection has occurred and is diagnosed, the virus is challenging to contain.
Have we seen RHDV and RHDV2 in Alberta?
Unfortunately, yes.
In August 2022, there have been eyewitness report that a group of stray feral rabbits has died suddenly in the Manchester Industrial area of Calgary. Dr. Patel who works in the Office of the Chief Provincial Veterinarian confirmed with the Avian and Exotic Pet Clinic that the rabbits submitted for RHD testing were positive for the virus.
In May 2022, a dead domestic rabbit was examined by the University of Calgary and the Canadian Food Inspection Agency, where both labs confirmed the presence of the virus. The affected bunny was the only one in the household and was kept exclusively indoors. It is suspected that the contamination originated from local sourced hay on Kijiji.
In October 2021, RHDV was diagnosed in three dead young bunnies from a group of feral domestic rabbits located in the Northwest of Edmonton. It is also concerning that approximatively 50 rabbits from this group have disappeared or died in late September.
In May 2021, five bunnies in the MD of Taber suddenly died after contracting RHDV2. The animals were brought to a veterinary clinic in Lethbridge. To this day, the origins of this outbreak remain unknown and could not be traced back to the newest bunny in the household, who had been with the family for 6 months.
Multiple domestic rabbits have died from RHDV in Montana between February and March 2021, which suggests that both strains of RHDV are migrating North. It is plausible that the travel restrictions at the US borders due to the Covid-19 pandemic may have slowed down the introduction and spread of RHDV/RHDV2 into Alberta in 2020 and early 2021. However, it is probably just a matter of time before more cases are reported in the South of the province and possibly in Calgary.
British Columbia dealt with several cases of RHDV2 in the recent past. In 2018, an outbreak of RHDV2 was reported in Nanaimo, Comox and surrounding areas. In 2019, several bunnies from an apartment in downtown Vancouver died of RHDV, while four animals died of RHDV2 in Parksville.
Previously, cases were reported in Quebec and in Manitoba in 2016 and 2011, respectively.
How do you protect your bunny against RHDV?
Annual vaccination is the best protection against RHDV and RHDV2. Immunity is known to be achieved after 7 days.
Unfortunately, vaccination against the virus is not yet widespread in Canada. European vaccines (Eravac and Filavac) need to be imported under special permission from the Canadian Food Inspection Agency. Many clinics in the USA and Mexico have been able to procure enough vaccination doses to offer vaccination clinics to their local population of domestic bunnies, bunny shelters and sanctuaries.
Thankfully, a new Canadian distributor for the vaccine has been recently announced. A RHDV2 vaccine is also currently in the works in the USA (Medgene), while Mexico has created their own vaccine with significant success reported.
At the time this article was published and reviewed, we are aware of a few clinics in Calgary that are offering the vaccine. If more and more rabbit owners request the vaccine, more clinics and veterinary hospitals will carry it.
Veterinary clinics in Calgary and in Alberta who offer/offered the RHDV vaccine include:
Other steps to protect your rabbit from RHDV and RHDV2
What else can you do to protect your bunny from RHD?
Quarantine/isolate new rabbits coming into your household for 14 days.
Keep rabbits indoors and at home as much as possible.
Favor a professional pet sitter coming into your home to care for your bunny instead of a boarding facility when going away.
Protect your rabbits from flies, fleas and mosquitos.
Maintain good hygiene habits around your bunnies (e.g. hand washing, cage cleaning, etc.).
Do not feed your rabbits wild plants and grasses that may have been in contact with wild rabbits.
Avoid feeding hay and produce grown from outbreak areas.
Clean and disinfect new items like toys, dishes, trays and cages.
Leave shoes outside.
Do not approach or touch wild, stray or feral bunnies, dead or alive.
Do not import or bring home rabbit meat and fur.
What else can you do to help?
- Contact your veterinarian to inquire about the vaccine. The more people ask, the more likely the vaccine will become widely available. We should not wait for an outbreak in Calgary to have access to the vaccine.
- Contact your veterinarian immediately if your rabbit dies suddenly with no warning signs, or after displaying RHDV-like symptoms as described above. Wait for further instructions and do everything you can not to spread the virus outside of your home.
- Contact the Wildlife officials if you found a dead wild/stray/feral rabbit whose death is suspicious.
- JOIN the Facebook groups RHDV News Network and The North Americans RHDV Group to stay up to date with the latest news about RHDV and the efforts to stop the spread around the world and in North America.
Sources:
Alberta Government (link 1)
Alberta Government (link 2)
Comments