British Columbia

B.C. now has strict limits on rodent poisons. But advocates, industry are unsure how effective they'll be

This weekend, B.C. formally signed off on strict limits on several rodenticides aimed at reducing the secondary poisoning of other animals such as owls. Animal advocates and the pest management industry are unsure how helpful it will be.

Second-generation anticoagulant rodenticides can pose a risk of poisoning to animals that eat poisoned rodents

A rodent bait box sits on the dirt on a property in Vancouver.
An example of a rodent bait box. These boxes contain poisons which can then be spread to local predators who eat the animals being targeted. (Shawn Foss/CBC News)

Four years ago, Deanna Pfeifer had no idea discovering a dead owl in her Saanich, B.C., neighbourhood on Vancouver Island would lead her to become one of the staunchest advocates in the province for banning poisons meant to control rats and mice.

Pfeifer, a retired critical care nurse, had seen the owl many times before finding it dead on the ground, below where it often perched.

"As I held it in my arms, it was pretty healthy-looking," she said. "It didn't look like there was any injury and it didn't look like it had starved."

A necropsy found the bird died from toxins in its body that came from eating rodents poisoned with rodenticides.

"It wasn't an isolated incident I discovered," she said. "The more I started asking around, the more people were reporting to me that there were lots of owls dying and other pets as well."

Pfeifer, who worked as a nurse for 35 years, was outraged over the unintended consequence facing wildlife from pest control measures that seem to be ubiquitous. 

A woman kneels beside a camping cooler with four owls in plastic bags.
Deanna Pfeifer with four dead owls in Saanich B.C. She believes the animals died after secondary poisoning from rodenticides. (Submitted by Deanna Pfeifer)

She headed a campaign called Rodenticide Free B.C, which calls for the province to widely prohibit poisons used to control pests like rats and mice, and promote more holistic and multi-faceted solutions.

The more she spoke out, the more people contacted her about the dead owls they were finding. She eventually purchased a used walk-in freezer to preserve birds until the province could pick them up for testing.

"I just kept collecting them and they still keep coming," she said.

All the advocacy, from her and others, appeared to pay off. In July 2021, the province announced an 18-month ban on the sale and use of what's known as second-generation anticoagulant rodenticides (SGARs).

After a rat or mouse ingests them once, they powerfully interfere with blood clotting and cause the animal to die within four to 14 days. The poison works more quickly than first-generation anticoagulants, but stay longer in tissues, meaning they can be passed to non-target species

Owls are voracious hunters of rodents and can consume several each night.

"The abundant use of SGARs to control rodents has led to an unacceptable level of non-target wildlife poisonings," said an intentions paper from the province.

A mechanical mouse trap.
A mechanical mouse trap, which is an option for catching problem rodents as opposed to poison baited traps. (Shawn Foss/CBC News)

During the 18-month pilot ban, the province reviewed science on the topic, potential regulatory amendments and received around 1,600 public responses before announcing the changes would become permanent, effective this weekend with revision to its Integrated Pest Management Regulation.

"The changes will reduce unnecessary pesticide use by requiring individuals and businesses to focus on other methods of pest control, such as traps, less toxic rodenticide alternatives and removing food sources," said a release.

The regulation prohibits the sale and use of SGARs in B.C. for all members of the public, and most commercial and industrial operations.

Only select sectors deemed essential services, such as hospitals and food production, can purchase and use SGARs, but must meet requirements or hire a licensed pest-control company contracted to do the work. That includes holding a certificate and licence, having a site-specific integrated pest-management plan and recording its use.

"Records must be submitted to the ministry if requested," said the Ministry of Environment in a statement on Friday. "Any violations of ministry requirements can lead to penalties/disciplinary action."

Lukewarm response

Organizations representing pest control companies in B.C. and across Canada participated in the province's consultation over SGARs use and say the ban has taken away an important tool to keep rodent populations, which carry disease and can damage property, in check.

Sean Rollo, incoming president of the Canadian Pest Management Association, said SGARs can be used safely, especially in indoor settings, where there is low risk for a target rodent to become prey.

"I just think that there [could] have been a little bit more dialogue ... more concessions on the user groups and how the products were used rather than just blanket saying, 'OK you can't use them.'"

The association said since the SGARs ban went into place, its member companies have seen a spike in rodent activity across the province.

"I think it's too early to tell for sure if it was the temporary ban on the rodenticides that was causing this or if this is going to be something systemic long-term because of the ban of this active ingredient that we were using," said Rollo.


According to data from the City of Vancouver's 311 citizen-reporting system, in 2020 there were 1,138 cases that included the words 'rat', 'rodents' or 'mice' in the comments, which could indicate something like, "may attract rats/mice" as opposed to just sightings or infestations.

In 2021, the case numbers jumped to 1,175, and then up to 1,249 in 2022.

Meanwhile, advocates like Pfeifer say there are too many loopholes still allowing the application of SGARs and there are still several alternative poisons that can also harm non-target species.

"The action the province did take in response to our concern is not fulsome enough and animals continue to die," she said. "I'm still receiving owls, it has not stopped."

A rodent bait box sits next to a hole in the exterior wall of a B.C. property.
A rodent bait box sits next to a hole in the exterior wall of a B.C. property. Pest control experts say poisoning rodents should be a last resort after patching holes in structures and cleaning up food sources. (Joe Abercrombie/Humane Solutions Inc.)

Other pest control operators, like Joe Abercrombie — who since 2016 has been behind a company called Humane Solutions Inc., which eschews rodenticides in favour of pest-proofing structures — hopes the ban will create more awareness among property owners, demanding solutions to rodents other than poison.

He says the industry has become too reliant on rodenticides, and describes the product as an easy sell that creates steady revenue for companies, but produces dubious results.

"With poison, delayed onset anticoagulants literally mean that you don't know what is going on. How many rats ate that poison? You don't know. Did they get a lethal dose? You don't know. Did they die? You don't know. Where? You don't know."

'Complex and complicated issue'

Meanwhile scientists like Kaylee Byers, who studied rats as part of the Vancouver Rat Project, hopes the ongoing debate over pest control results in governments doing more meaningful research into the animals' co-existence with humans.


One study she was involved with showed when rat populations were reduced, the prevalence of disease among the remaining rats increased.

"One of the problems is that we treat rat management as a really simple solution. See a rat, lay down a trap, see a rat, put out some poison. Rat management is a very complex and complicated issue."


Chad Pawson is a CBC News reporter in Vancouver. Please contact him at