Brown dog tick

How to recognise it

These are the features that identify a brown dog tick. Each one is described in words so the identification works without the diagram.

1. Uniform reddish-brown with no white ornamentation on the shield, separating it from the American dog tick.
2. Elongated, narrow body outline rather than the rounded shape of Dermacentor species, 3 to 5 mm unfed.
3. The base of the mouthparts is hexagonal when viewed from above, which is characteristic of the genus.

What it leaves behind

• Ticks found indoors at all life stages — crawling up walls, around door frames, and in cracks — which no other US tick does.
• Heavy infestation of a dog and of its resting areas, kennels, and bedding.

Why an infestation persists

Uniquely among common US ticks, this species completes its entire life cycle indoors, so an infestation can build inside a home or kennel without any outdoor exposure. That single fact changes the whole approach, and it is why finding ticks climbing indoor walls points to this species. It can transmit Rocky Mountain spotted fever and canine ehrlichiosis.

Where it occurs

Throughout the United States, strongly associated with dogs and indoor environments.

Where to look for it

• Indoors, which is the diagnostic location — crawling up walls, around door and window frames, and along ceiling edges.
• Cracks and crevices near where a dog rests, including behind skirting and under carpet edges.
• Dog bedding, kennels, crates, and the vehicle a dog travels in.
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• Behind radiators and in the gaps of a kennel structure, where all life stages shelter.

When you see it, and why

There is effectively no season, and that is the key fact. This species completes its entire life cycle indoors, so a population builds inside a home or kennel year-round without any outdoor exposure at all. A household that has never walked its dog in long grass can still have an established infestation, which is why the indoor-only life cycle is worth knowing before anyone concludes the dog must have picked them up outside.

What getting the identification wrong costs you

Uniform reddish-brown with no white ornamentation separates it from the American dog tick, but the behavioural clue is stronger than the visual one: ticks climbing an interior wall are almost certainly this species, because no other common US tick completes its cycle indoors. Recognising that changes the whole approach, since treating the yard for a tick that never goes outside achieves nothing.

What a professional actually does

This needs veterinary and structural work together, and either one alone fails. The dog is the reservoir and is the veterinarian's side of the problem; the building holds every life stage in cracks and crevices and is the structural side. Ask how the plan addresses both, and expect thorough laundering and heat-drying of bedding plus crack and crevice work rather than a surface spray.