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Ticks in Ohio

Common species, seasonal activity, exposure scenarios, what to do after a bite, and the state’s tick-identification options. Sourced from the state health department + university extension.

STATE COUNTY RANGE MAP
rendered 2026-05-25
Blacklegged tick activity by Ohio county
Blacklegged tick activity by Ohio county
ODH surveillance · 2024-2025 season
Source: ODH + Ohio State Buckeye Tick Test Lab + ODA + CDC TickNET (placeholder baseline; awaiting ODH county-level import. Ohio is an active expansion zone — county data is genuinely useful here)

Common species in Ohio

Ohio follows the state health led source pattern. The species below are drawn from the state-authority sources listed in the sidebar Data Row.

III
4-6 mm
Macro photo of an unfed adult american dog tick with a millimeter scale
American dog tick
Dermacentor variabilis
Identify →
IV
4-6 mm
Macro photo of an unfed adult lone star tick with a millimeter scale
Lone star tick
Amblyomma americanum
Identify →
V
3-4 mm
Macro photo of an unfed adult brown dog tick with a millimeter scale
Brown dog tick
Rhipicephalus sanguineus
Identify →
SECONDARY
EMERGING WATCH

When ticks are most active

Broad caution April through October. American dog tick peaks spring-summer; blacklegged tick nymphs peak May-July (eastern + southeastern Ohio leads); lone star tick activity May-August expanding northward. Ohio is genuinely a multi-tick frontier — populations vary sharply by county.

Status:source caveated editorial

Where you're most likely to encounter ticks

Hocking Hills State Park hiking, Cuyahoga Valley National Park, Mohican State Park + Mohican-Memorial State Forest, Wayne National Forest (southeast Ohio Lyme corridor), Lake Erie shore trails, Columbus + Cleveland + Cincinnati suburban edges, Amish Country trails, hunting properties statewide, dog walking in any wooded or tall-grass edge.

Disease context

Each disease named below carries an evidence tag per the Data Row policy. Pills indicate the strength of state-specific evidence, not the severity of the disease. Symptoms should always be routed to a clinician; this is orientation, not diagnosis.

  • Lyme diseasestate surveillance confirmed

    ODH publishes Lyme surveillance; eastern + southeastern Ohio counties leading. Ohio is a Lyme-expansion frontier — cases growing year over year

  • Rocky Mountain spotted feverstate surveillance confirmed
  • Ehrlichiosisstate surveillance confirmed
  • Anaplasmosisstate surveillance confirmed
  • Powassan virus diseasestate surveillance confirmed

    Rare but documented in Ohio surveillance

  • Alpha-gal syndromeregional pattern

    Lone star expansion + Ohio in the watch zone

  • Babesiosisnon diagnostic mention only
  • STARInon diagnostic mention only

If you find a tick — what to do

Tick-ID program status:state id program uncertain

Map resolution notes

mixed resolution.ODH publishes county-level Lyme + tickborne disease data. Ohio is an active expansion zone — county-resolution data is genuinely useful here because risk varies sharply between eastern (high) and western (low) Ohio. CDC maps support national comparison.

State sources

Primary species source
Ohio Department of Health (ODH) Zoonotic Disease Program + Tick-Borne Disease hub; Ohio State University Extension entomology publications and the Ohio State Buckeye Tick Test Lab.
Primary health source
ODH Zoonotic Disease Program tickborne disease surveillance + reportable disease summaries; CDC pages and maps for national guardrails.
Primary extension source
Ohio State University Extension (Ohio State Extension Service) publications on OH tick species, yard/property tick management, and lone star + blacklegged tick expansion.
Surveillance
ODH county-level Lyme + tickborne disease surveillance; Ohio Department of Agriculture (ODA) animal-health + Asian longhorned tick monitoring; Ohio State Buckeye Tick Test Lab for species + pathogen prevalence data; CDC for national comparison.