Deer tick
Ixodes scapularis
Not established in Arizona
- 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
Tick Identification in Arizona
The ticks you are most likely to find in Arizona, 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.
Carries Lyme
American dog tick
Dermacentor variabilis
Reported in Arizona
- Size:
- Larger, an apple seed
- Look for:
- Brown with an ornate off-white mottled shield
- Carries:
- Rocky Mountain spotted fever, tularemia (rare)
Lone star tick
Amblyomma americanum
Not established in Arizona
- Size:
- Medium, rounded
- Look for:
- Reddish-brown; female has a single white dot on the back
- Carries:
- Ehrlichiosis, STARI, alpha-gal syndrome
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
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
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
Rocky Mountain wood tick
Dermacentor andersoni
Reported in Arizona
- Size:
- Larger, an apple seed
- Look for:
- Brown with an ornate off-white and gray marbled shield
- Carries:
- Rocky Mountain spotted fever, Colorado tick fever, tularemia
Pacific Coast tick
Dermacentor occidentalis
Not established in Arizona
- Size:
- Larger, an apple seed
- Look for:
- Brown with a marbled silvery-gray ornate shield
- Carries:
- Pacific Coast tick fever, tularemia
Arizona 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 Arizona county
These are the three ticks CDC maps county by county, not the only ticks in Arizona: the brown dog, Gulf Coast, and Asian longhorned ticks are in the chart above. Tap a county for its daily tick-risk detail.
| County | Deer tick | American dog tick | Lone star tick |
|---|---|---|---|
| Apache County | Not established | Reported | Not established |
| Cochise County | Not established | Reported | Not established |
| Coconino County | Not established | Reported | Not established |
| Gila County | Not established | Reported | Not established |
| Graham County | Not established | Reported | Not established |
| Greenlee County | Not established | Reported | Not established |
| La Paz County | Not established | Reported | Not established |
| Maricopa County | Not established | Reported | Not established |
| Mohave County | Not established | Reported | Not established |
| Navajo County | Not established | Reported | Not established |
| Pima County | Not established | Reported | Not established |
| Pinal County | Not established | Reported | Not established |
| Santa Cruz County | Not established | Reported | Not established |
| Yavapai County | Not established | Reported | Not established |
| Yuma County | Not established | Reported | Not established |
Do not overlook the tiny ones
Nymph deer ticks are the size of a poppy seed and cause most Lyme cases in Arizona 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 Arizona?
- Arizona has the deer tick (blacklegged tick), which carries Lyme disease and is not established across the state; the American dog tick, which is reported; and the lone star tick, which is not established and causes alpha-gal syndrome. County-level presence is shown in the table above.
- Which Arizona tick carries Lyme disease?
- The deer tick, also called the blacklegged tick, is the tick that spreads Lyme disease in Arizona. The American dog tick and lone star tick do not carry Lyme, though they can transmit other illnesses.
- Are there lone star ticks in Arizona?
- The lone star tick is not established in Arizona 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.