By Thomas Smith

Eight wildlife rehabilitation centres have banded together in a call to action against the use of rodenticides in Ontario. More commonly called rat poison, the sanctuaries that have taken up the call include Aspen Valley Wildlife Sanctuary in Rosseau, Holly’s Have Wildlife Rescue in Ottawa, Procyon Wildlife in New Tecumseth, Sandy Pines Wildlife Centre in Napanee, Shades of Hope Wildlife Rescue in Pefferlaw, Muskoka Wildlife Centre, Turtle Pond Wildlife Centre in Sudbury, and Haliburton’s own Woodlands Wildlife Sanctuary.

There are three types of rodenticides commercially available including first and second-generation anticoagulants and acute toxicants. The first-generation and second-generation anticoagulants cause lethal blood hemorrhaging within animals, making them die from internal bleeding. Acute toxicants may include zinc phosphate, alpha-chloralose, or strychnine. Each of these acute toxicants causing extreme pain before death and when ingested, are typically untreatable.

Anticoagulant rodenticides are the most dangerous to non-targeted animals. Both pets and wildlife are susceptible to being poisoned from them.

“Sometimes when we get the animals, they are too far gone,” said Monika Melichar, founder of Woodlands Wildlife Sanctuary. “When a wild animal is allowing itself to get caught by hand, it isn’t a good sign.”

“The poisons are flavored to make them attracted to it,” said Allison Hansen, founder of Rodenticide Free Ontario. “When you are putting them around your building, you are drawing rodents and other species towards your building. They just think it’s food.”

Hansen says that robins, bears, and raccoons have been observed eating poisoned bait intended to kill rodents.

“Deal with garbage properly. Rinse your recyclables, put your garbage in a container not accessible by wildlife and identify and seal any entryways in your home,” said Hansen. “The bonus to that is it is cheaper in the long run and your home becomes more energy efficient.”

Hansen says that Horseshoe Lake Property Owners Association has adopted a rodenticide-free policy. While unenforceable, Hansen is hopeful for the awareness of the dangers rat poison can cause with the local wildlife.

A 2020 study from the Cummings School of Veterinary Medicine found that 100 per cent of red-tailed hawks that were examined had traces of anticoagulant poisons in their system. A 2024 study published in the Canadian Journal of Zoology found that 17 per cent of the river otters they analyzed had traces of anticoagulant rodenticide.

“Before you leave your cottage, make sure to leave it mouse clean, not human clean,” said Hansen. Leaving your space mouse clean would include cleaning your appliances, not leaving any food in your cupboards, cleaning your barbecue, and removing any items like scented soaps or creams that may attract animals.

Hansen says that there are several companies that service Haliburton County in rodent-proofing your house. If you are looking for a list of qualified professionals, she asks you to email her at hansenallisonm@gmail.com.

Many residents and seasonal visitors feed wildlife like deer, chipmunks, and squirrels. Melichar advises against feeding wild animals and planting gardens that can provide food to wildlife.

“Let the animals be naturally in the environment around you,” said Melichar. “We have had a hummingbird come in that has had its tongue extended permanently. That is from a fungus due to improper cleaning of a hummingbird feeder.”

Beneficial flowers such as beebalm and lavender will attract hummingbirds and beneficial insects.

“The winter is a different story,” said Melichar, “The winters are harsh, so supplementing them is appropriate during harsh winters.”

In 2024, the Echo covered the story of Slater, a red tailed hawk that had been poisoned after ingesting a rodent that had been poisoned with anticoagulants. Melcihar has reported that Slater had a full recovery and was released in the same area in which he was found.

“I think we are becoming much more aware of rodenticide poisoning now,” said Melichar. “I wasn’t aware of the wildlife that had been coming into our care that could have been poisoned. We didn’t really think about it.”

Melichar says that wildlife poisonings act in a domino effect. From the poisoned mouse, to weasel, to fox, and vulture, each animal becomes poisoned along the food chain.

“The first poisoned mouse might not kill them, but maybe the third and fourth one might put them over the edge,” said Melichar. “The rodenticide in their bodies is not getting flushed out successfully. It bioaccumulates in their internal organs.”

Rodenticide poisoning spread throughout the environment, including into our waterways, poisoning trout and animals that feed on them.

Preventing animals from entering your building is the best solution for controlling rodents. If you desire to euthanize your pests, Melichar urges people to use snap traps that provide an instantaneous death, unlike glue traps that are needlessly cruel. Live traps are also an option, but must be checked regularly in order to release any caught animals.

If you are looking for an effective deterrent, Hansen recommends using sponges soaked in peppermint oil.

“We would love to ban it,” said Melichar.

“Lots of jurisdictions are starting to ban them around the world,” said Hansen. “They are starting to cause way too many problems along the food chain.”

Woodlands Wildlife Sanctuary is based in Haliburton and currently has around 120 animals in their care. Annually, the sanctuary treats around 800 animals.