Are tick populations rising in Ontario? How to protect yourself against them

CTV News

21-05-2025

This undated photo provided by the U.S. Centers for Disease Control and Prevention (CDC) shows a black-legged tick. THE CANADIAN PRESS/AP-CDC via AP
Not to tick you off, but the height of tick season is nearly here, and Ontario could see more of the pesky critters this year.
While it may be too soon to tell whether there will still be an upward trend in tick populations this summer, Manisha Kulkarni, professor of epidemiology and public health in the Faculty of Medicine at the University of Ottawa and researcher with the UPTick project, says that has been the common shift over the last few years.
'This trend has been going on for a number of decades, expanding out of the northeastern United States and it's attributed to a number of different factors—one of them being climate change,' Kulkarni explained.
Longer periods of warm weather allow the ticks to be more active, find hosts and reproduce, Kulkarni says, noting that warmer winter temperatures make it easier for these bugs to survive at higher altitudes.
Bernie Grafe, the GTA Residential Area Manager at Orkin Canada, said they have already started to see an uptick in tick activity this spring since wildlife has come out of hibernation and vegetation has started to grow back.
'Those ticks are now being transported with ease,' Grafe said. 'We had a very, very wet end of winter, which is seeing (a) significant increase in pest activity, including mosquitoes and ticks.'
What types of ticks live in Ontario? Where are they typically found?
The two tick species of note in Ontario are the ixodes scapularis, commonly called deer ticks or blacklegged ticks, and the American dog tick or wood tick.
Deer ticks are often found in Eastern Ontario, while dog ticks are spotted in southern Ontario, Kulkarni says. It also depends on the time of year for which ticks are most active, she adds.
Public Health Ontario says blacklegged ticks have established themselves along the north shores of Lake Erie, Lake Ontario and the St. Lawrence River, but have also been found in other areas like Haliburton, Kawartha, Muskoka, Thunder Bay and Lake of the Woods. The health agency has mapped out 'established risk areas' of where these ticks are, which it updates annually.
As for where they live, Kulkarni says deer ticks are often found in wooded or brushy areas as they rely on white-tailed deer to reproduce.
'It's going to be a higher percentage of them being in sort of wooded and forested areas, long grass areas, fields with sort of orphan-grown grass,' Grafe said, but said residential neighbourhoods with active chipmunk, raccoon, squirrel and mice populations could also see them pop up in their neighbourhoods as the rodents spread them to backyards.
That said, ticks can be found nearly anywhere as they can attach themselves to migratory birds, Kulkarni notes.
'We call these adventitious ticks or inventive ticks. They don't always establish a population in these areas,' Kulkarni said.
What diseases do ticks carry?
Deer ticks not only carry Lyme disease, but can also transmit other tick-borne pathogens like anaplasmosis, babesiosis and Powassan virus infection—which are all under surveillance in Ontario.
How to protect yourself from ticks
Wearing long clothing and applying Health Canada-approved insect repellent like DEET or icaridin can help repel or kill ticks, Kulkarni says. Also, wearing closed-toed shoes and tucking pants into your socks can help prevent ticks from burrowing into your skin.
'Being cautious when you come back home, doing a tick check—looking for any ticks that might be crawling on you or attached—and making sure to really remove those ticks promptly if they have been found,' Kulkarni said.
Kulkarni recommends consulting with a pharmacist to see if you're eligible for tick bite prophylaxis, which can help prevent infection if a tick did attach itself to your skin or had the opportunity to transmit any bacterium.
How to remove a tick
If a tick has latched itself onto your skin, the province recommends using fine-tipped tweezers to take hold of the bug—as close to your skin as possible—and pull it straight out with a gentle, but firm, grip.
It is crucial to not crush the tick, the province says, as it could cause Lyme bacteria to trickle into your bloodstream. The province also advises against using a lit match or cigarette, petroleum jelly, nail polish or nail polish remover, kerosene, or liquid soap to remove the tick.
'People have to be wary that when removing these ticks they have to be sure to also get the head,' Grafe told CTV News Toronto. Grafe notes this is due to the fact that ticks tend to bury their head underneath the skin.
Once the tick has been removed, the province advises to wash your skin with soap and water before disinfecting with rubbing alcohol or an iodine swab. Then place the tick in an airtight container, like an empty pill bottle, and identify what kind of bug it is before consulting with a health professional on next steps.
How to spot Lyme disease
'It's also really important to monitor for any symptoms like fever-like symptoms or rash—an expanding bullseye rash at the tick bite site. These are all signs that it could be a Lyme disease infection,' Kulkarni said. 'So it's really important to get assessed quickly by a healthcare provider.'
Other symptoms of Lyme disease include the chills, fatigue, headache, joint pains, muscle aches, spasms or tingling, and facial paralysis.
'It's usually the infants or teenager, immature ticks that will carry the Lyme disease, and they typically have to feed for about 24 hours,' Grafe said. 'So, if people catch this right away, they should be relatively safe.'
The number of cases of Lyme disease seen in Ontario have been on a steady rise since 2014, Kulkarni said, pointing to Public Health Ontario's data.
Over a decade ago, Ontario logged 257 cases of Lyme disease in the province. This number roughly septupled by 2023, where PHO reported 1,865 cases, including 84 who were hospitalized.
'The risk of acquiring Lyme disease in Toronto overall is believed to be low,' Toronto Public Health said in a statement.
Last year in Toronto, 57 blacklegged ticks tested positive for six tick-borne pathogens with nearly half of them carrying Borrelia burgdorferi, one of the causative agents of Lyme disease.