Torontonians will likely take advantage of the July long weekend to soak up some sun at parks and cottages. 

But outdoor enthusiasts should check themselves over to make sure they're not bringing back an unwanted guest, given the rise of ticks in southern Ontario, public health officials say.

Fiona Hunter, a medical entomologist at Brock University, said there's a rise in the number of blacklegged ticks — also known as deer ticks — being spotted in recent years. 

"What I was used to seeing was ticks up north on moose," Hunter said. "But now we're seeing many more ticks in the south."

Dr. Fiona Hunter

Fiona Hunter, an entomologist, says precautions should be taken before venturing into wooded areas as tick bites are often difficult to detect until after blood has been taken. (Dean Gariepy/CBC News)

She added that warmer winters have helped the tick populations grow.

"They're able to find lots of hosts to feed on and they have a high reproductive rate, especially when the winters aren't harsh enough to push the populations back."

The risk of contracting Lyme disease from a blacklegged tick bite remains low, according to Toronto Public Health, but a spokesperson there said they've kept a close watch on where the populations have been established. 

The city does a check for ticks in the spring and fall. In 2016, 183 blacklegged ticks were found in various parks, including Highland Creek and Algonquin Island Park. 

Tick

Ticks can often start as the size of a sentence period but will quickly grow after feeding. (Alessio Gasparotto)

Morningside Park has also been a problematic area, according to public health's 2016 numbers, said Dr. Christine Navarro, medical officer of health. 

"Particularly in the east end ... tick populations are established and maybe 30 per cent have Lyme bacteria," Navarro said.

In the Niagara region, where wooded areas are more common, the tick population increase is clear: there were 2,039 ticks reported in 2016; this year, there have already been 1,651 reported.

About 25 to 30 per cent of those are blacklegged ticks. 

Those who do find ticks on their clothing or pets shouldn't panic. The majority of the arachnids are dog ticks, which bite and draw blood but don't transmit Lyme disease, Hunter said.

Tips to avoid tick bites

Dr. Navarro said the city wants people to enjoy the outdoors, something she said they can do more safely by following these tips:  

  • Wear long sleeves and pants when walking through long grass

  • Use bug spray with Deet and incarnadine on exposed skin

  • Wear light coloured clothing to help spot attached ticks

  • Check clothing for ticks, which look like a small black dot, and take a shower or bath 

Hunter, meanwhile, recommended checking pets closely for ticks. Problem areas include the eyes, groin, ears and snout.