American Dog Tick

📐 FIELD GUIDE ILLUSTRATION

Original illustration by PestControlBasics.com. Use the labeled features above to confirm your identification.

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PestControlBasics Editorial Team

Reviewed by Derek Giordano · Updated 2026

🔍 Identification

Adults: 5-6mm unfed; reddish-brown with distinctive white/silver markings on scutum (dorsal plate) — different pattern in male vs female; much larger than deer tick. Active April-August. Found on: dogs, deer, rodents, and humans in grassy and brushy areas. Range: primarily eastern US east of the Rockies, plus Pacific Coast populations.

🧬 Biology & Behavior

American dog tick vectors Rocky Mountain Spotted Fever (Rickettsia rickettsii) — the most lethal tick-borne disease in the US with 20-25% mortality if untreated. Also vectors tularemia and can cause tick paralysis. Unlike deer tick (Lyme), RMSF requires only 2-20 hours of attachment for transmission — making tick checks critical but the time window shorter. RMSF can kill within 8 days of symptom onset without treatment. The classic rash appears 2-4 days after fever onset — appearing on wrists and ankles first.

⚠️ Damage & Health Risk

Rocky Mountain Spotted Fever — potentially fatal without prompt antibiotic treatment; tularemia; tick paralysis; standard tick bite reactions.

🔧 DIY Treatment

Permethrin-treated clothing for outdoor activities. DEET or picaridin on skin. Tick checks after outdoor activity — remove promptly. May and September perimeter bifenthrin spray on lawn edges and wooded borders.

👷 When to Call a Pro

Professional tick management programs with May and September spray plus tick tube placement reduces tick populations significantly.

❓ FAQ

What are the symptoms of Rocky Mountain Spotted Fever?

Initial symptoms: fever, headache, nausea — appear 2-14 days after bite. Rash appears 2-4 days after fever starts on wrists and ankles, spreading inward. The rash may not appear in all cases. If you develop fever and headache within 2 weeks of a tick bite, mention the tick bite to your doctor immediately — RMSF progresses rapidly and doxycycline works best when started early.

Is RMSF only in the Rocky Mountains?

No — the name is misleading. RMSF cases are most concentrated in the south-central and southeastern US (North Carolina, Oklahoma, Arkansas, Tennessee, Missouri) and the Pacific Coast. The American dog tick that transmits it lives throughout the eastern US and Pacific Coast states.

🕷️ American Dog Tick