Ticks spreading across Canada as climate warms — here's how to protect yourself

Ticks have been spreading across Canada for nearly a decade, and populations are now establishing in regions previously too cold to support them. Warmer winters and longer warm seasons are the primary drivers, according to Manisha Kulkarni, a professor in University of Ottawa's School of Epidemiology and Public Health.

"We're not seeing as cold winters that would normally prevent them from surviving and reproducing, so they're able to survive in more regions," Kulkarni said. Ontario now has 44 tick species in total, though only the blacklegged tick carries Lyme disease. The latest provincial maps show blacklegged tick populations as far north as Thunder Bay and Kenora, throughout the Ottawa Valley and in Owen Sound.

Insulating snow can also help ticks survive harsh winters. Ticks burrow into leaf litter blanketed by snow and stay protected even during stretches of -30 C weather.

To check yourself for ticks, Health Canada recommends covering as much surface area as possible: your chest, back, hair, armpits, belly button, between your toes, and the groin. Prevention includes wearing closed-toed shoes, long sleeves and pants with your shirt tucked in and pants tucked into your socks. Ten minutes in a hot dryer will kill any ticks that hitched a ride on your clothes. Sticking to cleared paths and trails also helps.

A University of Ottawa study recently found that spreading wood chips at the edges of gardens and trails where ticks are prevalent effectively reduced tick populations, suggesting a practical approach for outdoor spaces.