Ontario’s tick season worsening as winters get warmer

Thestar.com
May 15, 2023

While Richard Jarvis has never found a tick on his five-year-old dog Toro, he makes sure his pet gets anti-tick medications every month.

In April, Jarvis started giving his dog Simparica, a drug that kills the tick after it bites.

“The last couple of dogs, I used to take them for walks in the daytime down by the Grand River and occasionally, they’d get one,” he said.

Dog owners, like many other residents, are thinking about ticks as temperatures rise.

But Guelph researchers are saying ticks have become a problem year-round.

“We’re pretty much a 12-month tick season now,” said Scott Weese, a University of Guelph professor and microbiologist whose research focuses on bacterial infections in animals and humans.

Ticks come out once temperatures rise above 0C to 4C, a threshold that Waterloo Region hit for at least short periods during the winter months, said Weese.

There are many species of ticks, but black-legged ticks can spread Lyme disease to humans and pets. Ticks transmit the disease, caused by the bacterium Borrelia burgdorferi, after feeding on other infected animals, such as deer, birds, mice and chipmunks.

Waterloo Region is not considered a high-risk area for black-legged ticks with Lyme disease, according to the Ontario Lyme Disease Map from 2022. The map is updated annually.

Local cases of Lyme disease have fluctuated in the past decade, with 12 reported cases in 2021, the latest update from Public Health Ontario. The region saw the most reported cases -- 16 -- in 2019.

LYME Lyme disease rates in Ontario

The area with the highest number of reported cases in Ontario in 2021 was Kingston, Frontenac, Lennox and Addington, with 21 cases.

But it is still possible to encounter a black-legged tick almost anywhere in Ontario in their natural habitat, such as wooded or brushy areas.

“They can travel on birds and deer, so a black-legged tick can be found anywhere in Ontario,” said provincial public health inspector Rebecca Piovesan.

Because of this, people in Waterloo Region should protect themselves while outdoors: wear long sleeves, pants and closed-toe shoes; tuck pants into socks; choose lighter-coloured clothes; use bug spray with DEET or Icaridin; and stay on trails.

Lyme disease is a disease of public health significance, meaning each case must be reported to the region’s public health unit within at least one business day.

A tick bite will not be itchy, painful or sometimes even visible, but the effects can be serious.

Headaches, fever, fatigue and skin rashes are all symptoms of Lyme disease. If left untreated, the disease can affect joints, the heart and the nervous system.

Most cases of Lyme disease come from nymphs -- ticks the size of a poppyseed, and adult female ticks, which are the size of a sesame seed.

The tick must be attached for at least 24 hours to transmit the disease, which is why experts encourage people to do “tick checks” after spending time outside or in the grass.

This helps so tick can be found before or soon after a bite, “and you can remove them correctly to try and minimize the risk of some of these diseases,” said Justin Wood, a Guelph-based researcher who founded Geneticks, a private lab that tests for tick-borne diseases. People across Canada send ticks to Geneticks, which then tests them for diseases.

The lab usually gets ticks sent in from March until around mid-December, Wood said.

This year, for the first time, people were sending ticks in January and February.

Ticks that survive winter have more time to reproduce, said Wood, and “that leads to other problems as well.”

With more ticks, and ticks that are active for longer periods, the bugs have more time to migrate to other, newer areas, he said.

“That means that people that formerly lived outside of the normal range of a lot of these species are starting to encounter them more frequently than they were before,” he said.

There is no medication available for humans to prevent tick bites, but bug repellent sprays help.

The best solution for pets is preventive medication, like the one Jarvis gives to Toro every month, researcher Weese said.

Options that prevent ticks from attaching to a pet, or that kill the tick shortly after attaching are the “cornerstone for prevention of tick-borne diseases,” Weese said.

“There is a Lyme disease vaccine for dogs and while it’s useful, it’s very much a Plan B approach, since preventing ticks from feeding on a dog is a better way to prevent Lyme disease,” he said.

If you find a tick, you can submit photos to the provincial site etick.ca for identification.