If you’ve spotted a raccoon acting strangely recently, perhaps wandering close to humans, getting up on its hind legs or baring its teeth, you might have spotted a sign of the “zombie virus” — a sickness that has been spreading among raccoons across Toronto.

Each year, the Ontario Wildlife Centre receives hundreds of calls from homeowners who believe they’ve encountered a raccoon with rabies, but a large portion of the reported cases turn out to be raccoons suffering from something called canine distemper virus (CDV).

CDV results in raccoons and mammals acting “zombie-like.” They might approach people or curl up to sleep in open areas close to people. They generally act disoriented or lethargic, like they’re about to pass out, but they can also become aggressive if cornered or have seizures.

In Toronto, canine distemper has been “constant” among raccoons and other animals for the past 15-20 years, according to Nathalie Karvonen, executive director of the Toronto Wildlife Centre animal hospital, and it was initially spread by dogs to raccoons. Most pets are now vaccinated against it, but not raccoons.

“I just talked to our hotline team about this yesterday, and they say they get calls pretty much every every single day [for sick raccoons], for years now — there’s an average of one a day,” she said. She’s also noted an increase in calls to their hotline regarding skunks with CDV.

Karvonen said it’s been really sad to see, because CDV is 100 per cent fatal for raccoons and other animals. “It’s contagious, it’s non-treatable, and it’s always horrible for them,” she said.

In April, Toronto Animal Services noted that the number of calls for sick and injured raccoons has spiked in 2024, with 3,600 calls so far this year compared to 719 between January and April 2022.

Last year, Toronto Public Health (TPH) advised residents to avoid physical contact with raccoons and all other wild animals (including approaching, touching, or feeding them) due to a significant increase in the number of sick and injured raccoons and the number of reported cases of people bitten and/or scratched by raccoons.

However, Karvonen noted that raccoons are not a danger to humans. “They’re not an animal that would just attack a human.” And since humans can’t catch CDV, you would be safe from the virus even in the case of a bite or scratch.

Since CDV causes raccoons to act differently, Karvonen said you may spot one hanging out in the middle of the afternoon on the sidewalk, or on your driveway in the pouring rain. “So the only potential danger might be for small children who might see a raccoon on the sidewalk and try to go up and pet it,” she said, “but it’s unlikely; these incidents just rarely happen.”

If you do spot a raccoon potentially with CDV, you should call your nearby wildlife centre — while a raccoon can’t be cured, it can be handled with care by animal control and your call will help stop the spread of the virus.

Unless someone were to fund a mass vaccination campaign for raccoons against CDV, Karvonen said the virus will just keep spreading, likely until the raccoons that are left develop a resistance to it. “With the West Nile virus, 20 years ago we were just getting nonstop birds, some of which were dying from the virus, and the more susceptible species was crows. Crows were almost entirely wiped out in Toronto at the time, and now you can see them coming back,” she said. “I would imagine that those would be crows that are resistant to the West Nile virus.”

“But I don’t think we’ll see raccoons wiped out at all,” Karvonen said. “They have a pretty large and stable population.”