! Symptoms & response !

What ticks can do.
And what to do about it.

Most tick bites in Canada are uneventful. The serious risk is real but narrow: it sits in the blacklegged tick’s range, in ticks attached for 24+ hours, and in a handful of diseases you can learn to recognize. What to watch for, and where to go if it happens.

What's out there

Tick-borne diseases in Canada.

Seven illnesses, from common to very rare. Open any of them for symptoms, how long the tick has to be attached, treatment, and where it shows up in Canada.

Lyme disease

moderate

Pathogen: Borrelia burgdorferi (bacterium)
Vector: Blacklegged tick
Onset: 3–30 days for rash; weeks to months systemic.

By far the most common tick-borne disease in Canada. Treatable with antibiotics in the early stages. The early sign is an expanding rash, bullseye or solid red.

Anaplasmosis

moderate

Pathogen: Anaplasma phagocytophilum
Vector: Blacklegged tick
Onset: 1–2 weeks after bite.

Often turns up with Lyme, since the same tick can carry both. Looks like a bad flu with no cough or runny nose. Treatable with doxycycline.

Babesiosis

moderate

Pathogen: Babesia microti (protozoan)
Vector: Blacklegged tick
Onset: 1–4 weeks after bite, sometimes longer.

A malaria-like parasite that infects red blood cells. Rare in Canada but rising where blacklegged ticks live. Can be severe in older people and anyone without a spleen.

Powassan virus

severe

Pathogen: Powassan virus (flavivirus)
Vector: Blacklegged tick; also I. cookei
Onset: 1 week to 1 month after bite.

Rare but very serious, with no antiviral treatment. About 10% of confirmed cases are fatal, and many survivors have lasting neurological damage. Transmission can happen within minutes of attachment.

Ehrlichiosis

moderate

Pathogen: Ehrlichia chaffeensis
Vector: Lone Star tick; blacklegged tick
Onset: 1–2 weeks after bite.

Rising in Canada as the Lone Star tick establishes in southern Ontario. Looks like anaplasmosis, sometimes with a rash. Treatable with doxycycline.

Rocky Mountain spotted fever

severe

Pathogen: Rickettsia rickettsii
Vector: American dog tick; Rocky Mountain wood tick
Onset: 2–14 days after bite.

Very rare in Canada but fatal in 15–30% of untreated cases. Look for a rash that starts on the wrists and ankles. Doxycycline starts on suspicion, before the lab confirms.

Alpha-gal syndrome

chronic

Pathogen: Alpha-gal carbohydrate (allergen)
Vector: Lone Star tick
Onset: Weeks to months (a delayed allergy).

An allergy, not an infection. Repeated Lone Star tick bites can leave you allergic to red meat, with reactions hours after eating beef, pork, or lamb. Anaphylaxis is possible.

Where to go

Pharmacist, doctor, or ER.

Where to go depends on what’s happening and when.

Pharmacist

When

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

What

In Ontario, a pharmacist can prescribe a single preventive dose of doxycycline if you meet the criteria: deer tick, attached 24 hours or more, within 72 hours of removal, no allergy. Walk in with the tick on a card. See the removal page for full criteria. Other provinces handle this differently, so check with your local pharmacy regulator.

Walk-in clinic or family doctor

When

Symptoms appearing within 30 days of a bite.

What

Expanding rash (bullseye or solid red, anywhere on the body), unexplained fever, joint or muscle pain, severe fatigue, headaches that won’t quit, swollen lymph nodes. Bring the tick if you saved it. The earlier antibiotics start, the better the outcome.

Emergency room, or call 911

When

Severe symptoms within a month of a bite.

What

Confusion, severe headache, neck stiffness, seizures, facial weakness on one side, sudden vision changes, difficulty breathing, anaphylaxis. These can be signs of Powassan virus encephalitis, late-disseminated Lyme, anaphylactic alpha-gal reaction, or other serious tick-borne illness. Don’t wait it out.

Tick testing

Two Canadian labs that test the tick itself.

Testing the tick is sometimes faster and more reliable than testing your blood, because the antibody response takes weeks to show up. If you saved the tick, two Canadian options:

Free

eTick.ca

A Canadian site (run by Bishop’s University) that identifies your tick from a photo. Free, and usually back to you within a few days. Your submission also helps build the national tick-tracking map. etick.ca

Paid, PCR testing

Geneticks

Tests the tick itself by PCR for Borrelia (Lyme), Anaplasma, Babesia, Borrelia miyamotoi, and Powassan. Turnaround typically under a week. Cost varies by panel. geneticks.ca

A positive tick test means the tick carried a pathogen, not that it passed it to you. A negative test is reassuring but not a guarantee. Weigh the result alongside your symptoms and how long the tick was attached.

After the tick is off - the 30-day watch and when each symptom matters.
How to safely remove a tick - including the Ontario pharmacist 72-hour preventive window.
Tick season in Canada - when ticks are active, by province and month.
For my kid - when to escalate for a child who can’t tell you what hurts.
For my pet - including the dog Lyme vaccine (humans don’t have one yet).

Last reviewed May 30, 2026

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

What ticks can do.
And what to do about it.

Tick-borne diseases in Canada.

Lyme disease

Anaplasmosis

Babesiosis

Powassan virus

Ehrlichiosis

Rocky Mountain spotted fever

Alpha-gal syndrome

Pharmacist, doctor, or ER.

Pharmacist

Walk-in clinic or family doctor

Emergency room, or call 911

Two Canadian labs that test the tick itself.

eTick.ca

Geneticks

More from the field guide.

Seasonal alerts for your inbox.

What ticks can do.And what to do about it.

Tick-borne diseases in Canada.

Lyme disease

Anaplasmosis

Babesiosis

Powassan virus

Ehrlichiosis

Rocky Mountain spotted fever

Alpha-gal syndrome

Pharmacist, doctor, or ER.

Pharmacist

Walk-in clinic or family doctor

Emergency room, or call 911

Two Canadian labs that test the tick itself.

eTick.ca

Geneticks

More from the field guide.

Seasonal alerts for your inbox.

What ticks can do.
And what to do about it.