Tick Identification in Wisconsin

The ticks you are most likely to find in Wisconsin, with photos and the size, color, and markings that tell them apart. Only the deer tick carries Lyme disease. Below the chart, see which types live in your county.

Female deer tick (blacklegged tick) on a green leaf, with a reddish-orange body, dark shield, and black legs, no white markings

Deer tick

Ixodes scapularis

Carries Lyme

Established in Wisconsin

Size:
Small, a sesame seed (nymph: a poppy seed)
Look for:
Reddish-orange body, solid dark shield, black legs, no pattern
Carries:
Lyme, babesiosis, anaplasmosis, Powassan
Full deer tick guide →
Female American dog tick with an ornate off-white and brown mottled shield behind the head

American dog tick

Dermacentor variabilis

Established in Wisconsin

Size:
Larger, an apple seed
Look for:
Brown with an ornate off-white mottled shield
Carries:
Rocky Mountain spotted fever, tularemia (rare)
Full american dog tick guide →
Female lone star tick on a green blade of grass, reddish-brown with a single bright white dot in the center of its back

Lone star tick

Amblyomma americanum

Not established in Wisconsin

Size:
Medium, rounded
Look for:
Reddish-brown; female has a single white dot on the back
Carries:
Ehrlichiosis, STARI, alpha-gal syndrome
Full lone star tick guide →
Female brown dog tick, uniform reddish-brown with no distinct markings

Brown dog tick

Rhipicephalus sanguineus

Found nationwide, the one tick that infests homes and kennels indoors

Size:
Medium, narrow body that tapers toward the head
Look for:
Uniform reddish-brown, no ornate markings
Carries:
Rocky Mountain spotted fever, canine diseases
Full brown dog tick guide →
Female Gulf Coast tick with an ornate silvery patterned shield

Gulf Coast tick

Amblyomma maculatum

A southern tick spreading north into the mid-Atlantic

Size:
Large, bigger than a lone star
Look for:
Silvery ornate markings on the shield, no single dot
Carries:
Rickettsia parkeri spotted fever
Full gulf coast tick guide →
Female Asian longhorned tick, small and uniform reddish-brown with no markings

Asian longhorned tick

Haemaphysalis longicornis

A newer arrival, established in the mid-Atlantic and spreading north

Size:
Small and plain, often found in large numbers
Look for:
Reddish-brown with no markings
Carries:
Mainly a livestock threat; human disease risk under study
Full asian longhorned tick guide →

Wisconsin establishment is shown for the three ticks CDC tracks by county; the others carry a regional range note. Source: CDC tick surveillance (ArboNET Tick Module), 2025. County surveillance is coarse: “not established” is a lack of records, not proof a tick is absent.

Deer, dog and lone star ticks by Wisconsin county

These are the three ticks CDC maps county by county, not the only ticks in Wisconsin: the brown dog, Gulf Coast, and Asian longhorned ticks are in the chart above. Tap a county for its daily tick-risk detail.

CountyDeer tickAmerican dog tickLone star tick
Adams CountyEstablishedEstablishedNot established
Ashland CountyEstablishedEstablishedNot established
Barron CountyEstablishedEstablishedNot established
Bayfield CountyEstablishedEstablishedNot established
Brown CountyEstablishedEstablishedNot established
Buffalo CountyEstablishedEstablishedNot established
Burnett CountyEstablishedEstablishedNot established
Calumet CountyEstablishedEstablishedNot established
Chippewa CountyEstablishedEstablishedNot established
Clark CountyEstablishedEstablishedNot established
Columbia CountyEstablishedEstablishedNot established
Crawford CountyEstablishedEstablishedNot established
Dane CountyEstablishedEstablishedNot established
Dodge CountyEstablishedEstablishedNot established
Door CountyEstablishedEstablishedNot established
Douglas CountyEstablishedEstablishedNot established
Dunn CountyEstablishedEstablishedNot established
Eau Claire CountyEstablishedEstablishedNot established
Fond du Lac CountyEstablishedEstablishedNot established
Forest CountyEstablishedEstablishedNot established
Grant CountyEstablishedEstablishedNot established
Green CountyEstablishedEstablishedNot established
Green Lake CountyEstablishedEstablishedNot established
Iowa CountyEstablishedEstablishedNot established
Iron CountyEstablishedEstablishedNot established
Jackson CountyEstablishedEstablishedNot established
Jefferson CountyEstablishedEstablishedNot established
Juneau CountyEstablishedEstablishedNot established
Kenosha CountyEstablishedEstablishedNot established
Kewaunee CountyEstablishedEstablishedNot established
La Crosse CountyEstablishedEstablishedNot established
Lafayette CountyEstablishedEstablishedNot established
Langlade CountyEstablishedEstablishedNot established
Lincoln CountyEstablishedEstablishedNot established
Manitowoc CountyEstablishedEstablishedNot established
Marathon CountyEstablishedEstablishedNot established
Marinette CountyEstablishedEstablishedNot established
Marquette CountyEstablishedEstablishedNot established
Milwaukee CountyEstablishedEstablishedNot established
Monroe CountyEstablishedEstablishedNot established
Oconto CountyEstablishedEstablishedNot established
Oneida CountyEstablishedEstablishedNot established
Outagamie CountyEstablishedEstablishedNot established
Ozaukee CountyEstablishedEstablishedNot established
Pepin CountyEstablishedEstablishedNot established
Pierce CountyEstablishedEstablishedNot established
Polk CountyEstablishedEstablishedNot established
Portage CountyEstablishedEstablishedNot established
Price CountyEstablishedEstablishedNot established
Racine CountyEstablishedEstablishedNot established
Richland CountyEstablishedEstablishedNot established
Rock CountyEstablishedEstablishedNot established
Rusk CountyEstablishedEstablishedNot established
Sauk CountyEstablishedEstablishedNot established
Sawyer CountyEstablishedEstablishedNot established
Shawano CountyEstablishedEstablishedNot established
Sheboygan CountyEstablishedEstablishedNot established
St. Croix CountyEstablishedEstablishedNot established
Taylor CountyEstablishedEstablishedNot established
Trempealeau CountyEstablishedEstablishedNot established
Vernon CountyEstablishedEstablishedNot established
Vilas CountyEstablishedEstablishedNot established
Walworth CountyEstablishedEstablishedNot established
Washburn CountyEstablishedEstablishedNot established
Washington CountyEstablishedEstablishedNot established
Waukesha CountyEstablishedEstablishedNot established
Waupaca CountyEstablishedEstablishedNot established
Waushara CountyEstablishedEstablishedNot established
Winnebago CountyEstablishedEstablishedNot established
Wood CountyEstablishedEstablishedNot established

Do not overlook the tiny ones

Nymph deer ticks are the size of a poppy seed and cause most Lyme cases in Wisconsin because they are so easy to miss. When you check for ticks, look for the small ones too, especially in June and July.

Frequently asked questions

What types of ticks live in Wisconsin?
Wisconsin has the deer tick (blacklegged tick), which carries Lyme disease and is established across the state; the American dog tick, which is established; and the lone star tick, which is not established and causes alpha-gal syndrome. County-level presence is shown in the table above.
Which Wisconsin tick carries Lyme disease?
The deer tick, also called the blacklegged tick, is the tick that spreads Lyme disease in Wisconsin. The American dog tick and lone star tick do not carry Lyme, though they can transmit other illnesses.
Are there lone star ticks in Wisconsin?
The lone star tick is not established in Wisconsin in current CDC county surveillance, but ranges are expanding northward, so this can change. It causes alpha-gal syndrome, a red-meat allergy.
How can I tell these ticks apart?
Use size, color, and legs. The deer tick is small with a reddish-orange body, a solid dark shield, and black legs. The American dog tick is larger and brown with an ornate off-white mottled shield. The female lone star tick has a single white dot on her back. The chart above shows each one.