Enjoy a tick-safe summer in Canada

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Removal · ID · risks
Prevention · for Canada

!   The 30-day watch   !

After removal.
What to watch for.

The tick is off. Most of the time, that’s the end of it. But Lyme and the other tick-borne illnesses take days to weeks to show up, and the textbook bullseye you were warned about doesn’t appear in most Canadian cases.

The big misconception

Most Lyme cases never have a bullseye.

The textbook rash (erythema migrans, a clear centre ringed by a red halo) is the cleanest sign of early Lyme. It’s also the exception. Canadian and US case data consistently show that fewer than half of confirmed Lyme infections produce a recognizable bullseye. Many produce a solid red expanding patch, an oval blotch, or no rash at all.

Treat all of these as suspect

What counts as a Lyme rash.

  • A bullseye target (red ring around a clear or lighter centre).
  • A solid red, expanding patch larger than a loonie.
  • An oval or irregular red zone that grows over days, warm or not.
  • Any new rash that appears 3 to 30 days after a bite, even if it’s not at the bite site.

Photograph any of these with a ruler or coin for scale. A photo is more useful to a doctor than your memory of how big it was last Tuesday.

Also possible

A rash with no infection.

Not every red mark after a tick bite is Lyme. A small itchy red spot at the bite, no bigger than a coin and not growing, is almost certainly a normal reaction and clears on its own in a week or 2. The difference is expansion. Lyme rashes grow over days. Ordinary bite reactions don’t.

Week by week

What can show up when.

Different tick-borne illnesses show up on different schedules. Roughly;

Days 1–3

Almost certainly nothing

A small red itchy spot at the bite is normal and not Lyme. Lyme bacteria take days to produce symptoms, so anything in the first 48 hours is far more likely a normal bite reaction or an unrelated bug.

Days 3–14

The window for an expanding rash

If a Lyme rash is going to appear, this is when it most often does. Anaplasmosis and ehrlichiosis can also start here: high fever, severe headache, deep muscle aches with no cough or congestion.

Days 7–28

Systemic and neurological signs

Lyme can produce a flu-like illness with no rash: unexplained fever, fatigue, joint and muscle aches, headache, swollen lymph nodes. Facial palsy on one side (Bell's palsy) most often appears in this window too, as can heart-rhythm problems. Powassan virus (rare) can cause neurological symptoms here as well. Facial weakness on one side means a doctor today, not tomorrow.

Weeks 4 and beyond

Late presentations

Untreated Lyme can produce arthritis (especially the knees), brain fog, persistent fatigue or, less often, late facial palsy. Antibiotics still work at this stage but recovery takes longer. Tell a doctor about any of these if there was a tick bite weeks earlier.

Disease-by-disease symptoms and onset windows are on the risks page.

Where to go

Pharmacist, doctor, or ER.

Where you go depends on the symptom;

When

Within 72 hours of a deer-tick bite, no symptoms yet.

Pharmacist

Ontario only (as of 2026): a pharmacist can prescribe a single 200 mg preventive dose of doxycycline. Walk in with the tick on its card and your timeline. Criteria on the removal page. In other provinces this pathway varies.

When

Any expanding rash, or systemic symptoms within 30 days of a bite.

Walk-in or family doctor

Fever, fatigue, joint or muscle pain, a headache that won't quit, swollen lymph nodes, a rash anywhere on your body. Bring the tick if you saved it. Early antibiotics work very well for Lyme, and the earlier the better.

When

Severe or neurological symptoms within a month of a bite.

Emergency room (or 911)

Severe headache with neck stiffness, confusion, seizures, facial weakness on one side, sudden vision changes, chest pain or palpitations, anaphylaxis. These can be signs of Powassan encephalitis, disseminated Lyme, an alpha-gal reaction or other serious disease. Don't wait it out.

What to bring

The visit goes faster with 3 things.

  • The tick.Taped to its index card with the date and bite location written on it. If you didn’t save it, a clear photo is the next best thing.
  • The timeline. When the bite happened, when you removed the tick, when symptoms started. Rough days are better than no dates.
  • Where you were. The province, and ideally the area (a wooded part of Algonquin, a backyard in Lunenburg, a hike in Gatineau). A tick from a known Lyme zone is treated differently than one from northern Manitoba, where blacklegged ticks are still rare.

Related

More from the field guide.

Last reviewed

General information only, not medical advice. In an emergency, call 911. Read the full disclaimer.

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