CANMORE – Several feral rabbits are dropping dead in Canmore, but there has been no testing yet to confirm whether it is the fatal disease killing rabbits in Calgary.
Longtime resident Andrew Duff said he noticed the dozen or so rabbits that normally live on his street near Riverside Park completely disappeared on the weekend of Nov. 11-13.
He and others in the community, who have reported on social media many sudden and unexplained rabbit deaths throughout Canmore, wondered if it was Rabbit Hemorrhagic Disease (RHD), a highly contagious and fatal viral disease of rabbits.
“I found one dead rabbit on our front lawn with no apparent sign of trauma… it was just laying there and no injuries or anything – just dead,” Duff said, noting he has since seen other dead rabbits on nearby streets.
“I can confirm we had healthy rabbits on our street. Literally, you cannot walk on our street without seeing rabbits – four or five or six of them or more – and suddenly there was just none.”
Jennifer Davies, a trained veterinary pathologist who is the director of the diagnostic services unit and associate professor at the University of Calgary faculty of veterinary medicine, said RHD has not been confirmed in Canmore yet.
She said there are many things that can cause sudden and unexpected deaths in rabbits at this time of year such as inclement weather or starvation, or other infectious diseases or trauma that can cause a die-off of individuals or larger groups of rabbits.
“But one potential cause of an increased mortality in rabbits that one day seem healthy and the next day are dead is Rabbit Hemorrhagic Disease, caused by a highly contagious virus. We have confirmed that in the Calgary area, so it is possible in Canmore, but it is certainly not confirmed yet but we would like to know,” she said.
“If people are seeing that, please contact the Town of Canmore or the provincial authorities through the wildlife disease unit so that we can arrange to have carcasses brought into our lab and do the post-mortem examination and the viral testing to help confirm the diagnosis if it is there."
Initially, Duff decided to warn some neighbours, including one who lets her cat outside, because he thought the rabbits may have been poisoned.
He said he alerted the Town of Canmore about the dead rabbit in his yard on Nov. 17.
“Then I wondered if what was happening was because of that disease, and from what I understand it can wipe out a lot of them in 24 to 48 hours,” he said.
With temperatures hovering around – 10 Celsius to –15 C at the time, Duff said it wasn’t extremely cold when he found the carcass in his yard, and there was still some vegetation the rabbits were eating.
“It wasn’t the cold that suddenly wiped them out, it was definitely something else,” he said.
Town of Canmore officials say they are aware of recent social media discussions about dead rabbits, but say that municipal employees have not discovered any carcasses that could be sent in for testing.
“This has been something we have been aware of and we have been monitoring for some time,” said Caitlin Miller, manager of protective services for the Town of Canmore.
“Normally at this time of year we do see a decrease in the rabbit population – I am not a biologist so I am not going to speculate right now why – but it is a normal trend that we see throughout the years.”
With the heightened awareness of the RHD outbreak in Calgary this fall and in Edmonton last year, Miller said the Town of Canmore has been in contact with the province of Alberta.
“We’ve been speaking with the province over the summer about what the risk is,” she said.
“We do have a feral rabbit management program, but the risk is we don’t want it transmitting to our other natural wildlife.”
In addition, Miller said the Town of Canmore reached out to a provincial wildlife biologist earlier this week to ask about the testing process for a rabbit carcass if and when discovered, and was also in contact with Dr. Davies on Nov. 24.
“She gave us the process as to what to do and how to submit a rabbit for testing if we do come across any,” she said.
Meanwhile, The Town of Canmore’s feral rabbit trapping program undertaken by an independent contractor is ongoing. Feral rabbits, and their ability to draw large carnivores into town in search of a meal, were raised as a serious concern by the Bow Valley human-wildlife coexistence taskforce in 2018.
According to the municipality, 288 feral rabbits were captured between mid-January and early April this year, an increase of 57 per cent from the year before when 180 rabbits were trapped. It cost $51,341 in 2021 and $53,076 in 2022.
Since the trapping program began in 2012, $587,000 has been spent on removal of 2,130 feral rabbits, at a cost of $275.56 per rabbit.
The current budget set aside for 2023 is $55,000, but administration has brought forward a list of ideas to help advance goals in council’s strategic plan, including a proposal for an additional $35,000 for feral rabbit management for council’s consideration during budget deliberations.
“An option would be to put a bit more money in the pot for feral rabbit trapping to try to increase the number of rabbits we’re getting each year,” said Town CAO Sally Caudill in a recent meeting.
“We can tackle more rabbits, the more money we have the more we can do, but those are decisions for council to make.”
Miller said feral rabbits are managed in Canmore because they are an invasive species.
“They do cause damage to our municipal infrastructure, people's homes and private property,” she said.
Miller said the hope is to start trapping rabbits as part of the annual contract a little earlier – sometime next month as opposed to January 2023.
“We’re doing some targeted trapping in some of our higher rabbit populations areas just ahead of the January start,” she said.
Davies said Rabbit Hemorrhagic Disease is very specific to lagomorphs – rabbit and hare species.
“It won’t spread to other pet animals, to humans, to other wildlife species in that area, or to livestock within the province, so that’s an important note, it’s very rabbit-specific,” she said.
The strain of the disease is RHDV2, which can be transmitted between feral, domestic rabbits and indoor pet rabbits.
It also poses risk to native rabbit and hare species, such as jackrabbits, cottontails and snowshoe hares. Pikas are listed as a potentially susceptible species although Davies said she is unaware of any documented cases in them.
She said this newer strain, RHDV2, is different from the previous one, which only infected European rabbits, from which household and feral rabbit populations are derived, but did not pose a threat to wild lagomorph species in North America.
“But that changed in 2020 in the United States where they did notice the RHDV2 strain spread into the wildlife lagomorph population with quite a mass die-off of their jackrabbit and cottontail populations,” she said.
“So we are monitoring the situation closely to see if this virus is only going to affect those feral domestic rabbits or if there is potential risk to our wild rabbit species.”
Two animals in Calgary identified as mountain cottontails sent to the lab recently tested positive for RHDV2.
“They did die from Rabbit Hemorrhagic Disease and so we’re monitoring the situation very closely,” said Davies.
“We would like the public to notify us if they’re seeing die-offs of feral rabbits, but also if they're seeing die-off of our native species.”
Davies said RHD has been sporadically popping up in various locations in North America in the last few years. It was initially found in Canada on British Columbia’s Vancouver Island and the Gulf Islands in 2018, wiping out a considerable number of rabbits.
She said the virus has been confirmed in a few places in Alberta, including the Taber area in spring 2021, a small outbreak in Edmonton in fall 2021 and then a larger outbreak in the feral domestic rabbit population in Calgary this fall.
“It pops up in these quite widely-distanced geographic areas and most of the time we never know how it was introduced into that area,” Davies said. “It’s a highly resistant virus within the environment.”
The disease does not infect humans, but it is spread between rabbits through direct contact with infected saliva, runny nose and eyes, urine, manure, blood and infected fur or carcasses. It can also be spread by infected objects.
After being exposed to the virus, rabbits usually become sick within one to five days. Death is common after a short period of illness. Death may also occur suddenly without signs.
“There a lot of indirect transmissions so because the virus is out in the environment and it’s quite hardy, it can be picked up on car tires and transported from one area to another, on scavenging birds or on insects, on the bottom of people's shoes,” said Davies.
“There can be a lot of indirect transmissions so I guess it would be possible that it could spread from one location to another.”
Dead rabbits can be reported to Town of Canmore municipal enforcement at 403-678-4244.