American Dog Tick vs Brown Dog Tick: A Comparative Guide

folder_openArachnida, Ixodida
comment4 Comments

Ticks are small, blood-sucking arachnids that can transmit various diseases to humans and animals.

Two common species often encountered in the United States are the American dog tick and the brown dog tick.

The former is known to carry pathogens causing Rocky Mountain spotted fever and tularemia, while the latter is mainly associated with the transmission of Rocky Mountain spotted fever.

American Dog Tick
Brown Dog Tick

American Dog Tick vs Brown Dog Tick

The American dog tick (Dermacentor variabilis) is typically found in grassy or wooded areas, especially where there is abundant wildlife.

This tick will latch onto its host, either a human or an animal, and feed on its blood until it becomes engorged.

On the other hand, the brown dog tick (Rhipicephalus sanguineus) is more closely associated with dogs and can be found worldwide. It may also bite humans or other mammals.

Some key differences between these two tick species are their distribution, preferred hosts, and diseases they transmit.

For instance, the American dog tick is more frequently found in the eastern part of the United States, while the brown dog tick has a broader geographic distribution.

Besides, the American dog tick can transmit tularemia, which is not associated with the brown dog tick.

Identifying and understanding these ticks is essential for effective prevention and control measures.

Identification and Appearance

American Dog Tick

  • Adult female: Reddish-brown color with creamy-white dorsal shield on the back 1.
  • Size: Approximately ¼ inch long when unfed, up to ½ inch or longer when fully engorged 2.

Brown Dog Tick

  • Slightly different shape compared to American dog tick 3.
  • Reddish-brown color, lacks mottling found in Dermacentor species 4.
  • Size: slightly smaller than the American dog tick 5.

Geographical Distribution

American Dog Tick: Found in the United States, particularly in the eastern and central regions 6.

Brown Dog Tick: Found worldwide, but it is more commonly seen in the southwestern United States and along the U.S.-Mexico border 7.

Comparison Table

FeatureAmerican Dog TickBrown Dog Tick
Scientific NameDermacentor variabilisRhipicephalus sanguineus
AppearanceReddish-brown with white dorsal shieldReddish-brown, no mottling
SizeSlightly largerSlightly smaller
Geographical DistributionEastern and central United StatesSouthwest United States, U.S.-Mexico border, worldwide

Life Cycle and Habitat

The life cycle of both the American dog tick and the brown dog tick consists of four stages:

  • Egg
  • Larva
  • Nymph
  • Adult

The American dog tick requires three different hosts and at least 54 days to complete its life cycle. However, this can take up to two years depending on host availability, location, and temperature.

On the other hand, the brown dog tick also has a similar life cycle, involving multiple hosts.

Preferred Environment

American dog tick

  • Prefers grassy areas and walkways
  • Thrives in warmer weather

Brown dog tick

  • Tends to live in more urban environments
  • Adapts well to indoor living

Here’s a comparison table for a clearer overview:

AspectAmerican Dog TickBrown Dog Tick
Development StagesEgg, Larvae, Nymph, AdultEgg, Larvae, Nymph, Adult
Hosts RequiredThree different hostsMultiple hosts
Life Cycle Length54 days to 2 years, depending on host availability and temperatureSimilar timeline
Preferred HabitatGrassy areas, walkways, warmer weatherUrban environments, indoor living

When looking at their life cycle and habitats, the American dog tick and brown dog tick have similar developmental stages but differ in their preferred environments.


Both types of ticks require multiple hosts and can take up to two years to complete their life cycle stages.

However, it is important to know the specific habitat preferences of each tick to be able to identify and control them effectively.

Hosts and Feeding Behaviors

American dog tick:

  • Primary hosts: Medium-sized animals (e.g., raccoons, skunks, cats, dogs)
  • Secondary hosts: Small mammals (e.g., mice, voles, rats, chipmunks) 1

Brown dog tick:

  • Primary host: Dogs
  • May also bite humans and other mammals 2

Questing and Attachment

Questing: When ticks search for a host, they exhibit a behavior called questing. Both American dog ticks and brown dog ticks employ questing to find hosts 3.

Attachment: Once the tick finds a suitable host, it attaches to the skin by grasping and cutting into the surface. Then, it inserts its feeding tube for blood meal3.

Comparison Table

FactorAmerican Dog TickBrown Dog Tick
Primary HostsMedium-sized animals; dogsDogs
Secondary HostsSmall mammalsHumans and other mammals
Attachment MethodGrasps and cuts into skin; inserts feeding tubeGrasps and cuts into skin; inserts feeding tube

Tick-Borne Diseases

The American dog tick and brown dog tick can transmit various diseases such as Rocky Mountain spotted fever, Lyme disease, tularemia, ehrlichiosis, anaplasmosis, babesiosis, and tick paralysis.

Common symptoms among these diseases include fever, headache, fatigue, and muscle aches. Some diseases also manifest as a rash, which may help in detection.

DiseaseVectorPrimary Bacteria or Virus
Rocky Mountain Spotted FeverAmerican dog tick, brown dog tickRickettsia rickettsii
Lyme DiseaseBlacklegged tickBorrelia burgdorferi
TularemiaAmerican dog tickFrancisella tularensis
EhrlichiosisLone Star tickEhrlichia chaffeensis
AnaplasmosisBlacklegged tick, Western blacklegged tickAnaplasma phagocytophilum
BabesiosisBlacklegged tickBabesia microti
  • Rocky Mountain Spotted Fever causes a rash appearing on the wrists, ankles, and spreading further.
  • Lyme disease is marked by a “bull’s-eye” rash at the bite site.
  • Tularemia may cause an ulcer at the bite site and swollen lymph nodes.
  • Ehrlichiosis and anaplasmosis might have similar symptoms, but not always a rash.
  • Babesiosis can have flu-like symptoms, but in more severe cases present anemia.

Neurotoxins and Tick Paralysis

American dog ticks and brown dog ticks are known to produce a neurotoxin that may lead to a condition called tick paralysis, especially in pets.

Engorged adult female ticks are the primary carriers of this neurotoxin. Some common symptoms of tick paralysis in pets include:

  • Nausea
  • Vomiting
  • Difficulty walking or moving

To prevent tick paralysis, carefully check your pets for ticks after they spend time outdoors and remove any ticks as soon as possible.

Tick, possibly American Dog Tick

Prevention and Treatment

Preventing tick bites is a crucial step in avoiding tick-borne diseases:

  • Keep skin covered in tick-infested areas.
  • Use insect repellent containing DEET or permethrin.
  • Regularly check for ticks after being outdoors.

Most tick-borne diseases can be treated with antibiotics; however, early detection boosts chances of successful treatment.

  • Rocky Mountain Spotted Fever: Responds well to doxycycline if treated early.
  • Lyme disease: Can be treated with a 14-21 day course of antibiotics.
  • Tularemia: Streptomycin or gentamicin are effective antibiotics.
  • Ehrlichiosis: Treatable with doxycycline.
  • Anaplasmosis: Also treated with doxycycline.
  • Babesiosis: Typically requires a combination of atovaquone and azithromycin or clindamycin and quinine.

Note: Make sure to consult a healthcare professional for proper diagnosis and treatment.

Tick Management and Control

Chemical Methods

When dealing with American dog ticks and brown dog ticks, chemical control can be effective.

One popular option is acaricide. Acaricides are pesticides specifically designed to target ticks and kill them.

A key advantage of using acaricides is their efficiency in eliminating existing tick infestations near residences1.

However, there are some drawbacks to consider:

  • Potential harm to non-target species
  • Possible environmental contamination

Non-Chemical Methods

In addition to chemical methods, non-chemical approaches can be employed to manage ticks.

For instance, regular inspection of your pets and yourself for ticks can help prevent an infestation2.

Some common non-chemical methods include:

  • Grooming pets frequently
  • Keeping grass trimmed
  • Creating barriers between wooded areas and lawns

Comparison Table:

Chemical MethodsEffective at eliminating tick infestations1Harm to non-target species, environmental contamination
Non-Chemical MethodsEnvironmentally friendly, lower risk to non-target species2May require more frequent maintenance

To differentiate between American dog ticks and brown dog ticks, observe their scutum. The scutum is a hard plate on the back of ticks, and its color or pattern can help identify the tick species3.

Other Tick Species in the United States

There are several other tick species found in the United States, such as the Gulf Coast tick and the Rocky Mountain wood tick.

These ticks may also transmit various tick-borne diseases and cause problems like canine tick paralysis.

Here is a comparison table of these tick species:

Tick SpeciesPrimary RegionsDiseases TransmittedCan Cause Tick Paralysis
American Dog TickEastern and MidwestRocky Mountain Spotted Fever, TularemiaYes
Brown Dog TickWorldwideCanine Ehrlichiosis, Canine BabesiosisYes
Gulf Coast TickSoutheastern and Mid-Atlantic StatesRickettsia parkeri rickettsiosisNo
Rocky Mountain Wood TickRocky Mountain StatesRocky Mountain Spotted Fever, Colorado Tick Fever, TularemiaYes

Being aware of the different tick species in your region and taking appropriate preventive measures can help protect your pets and family from tick-borne diseases and tick paralysis.


Understanding the differences between the American dog tick and the brown dog tick is crucial for effective prevention and control of tick-borne diseases.

Their distinct habitats, hosts, and geographic distributions emphasize the importance of tailored strategies to protect humans and animals from these blood-sucking arachnids and the diseases they may transmit.

Now that you know how to protect yourself and your pets from these ticks, you can take the necessary measures.


  1. American Dog Tick – University of Maine Cooperative Extension 2 3 4

  2. American Dog Tick – University of Maine Cooperative Extension 2 3 4

  3. Biology and Management of Ticks in New Hampshire [fact sheet] – Extension 2 3 4

  4. Biology and Management of Ticks in New Hampshire [fact sheet] – Extension

  5. Biology and Management of Ticks in New Hampshire [fact sheet] – Extension

  6. American dog tick | Ticks | CDC

  7. Tick ID | Tick-borne Diseases | Ticks | CDC

Readers’ Mail

Over the years, has received hundreds of letters and some interesting images asking us about these ticks. Scroll down to have a look at some of them.

Letter 1 – Dog Tick or Deer Tick???

Subject: Engorged Tick
Location: Southern Connecticut
February 19, 2013 11:27 pm

Any way for a non-expert to tell the difference between an engorged dog vs. deer tick? Most internet images I’ve seen are very similar.
We found this on our bedroom carpet– we’re not convinced it was actually on our dog.
Signature: Fran Maurais


Hi Fran,
We don’t feel confident enough to distinguish between species of Ticks, but we are posting your images and perhaps one of our readers will be able to supply an answer.  Out gut feeling is that this is a Dog Tick. 

You can also search BugGuide for images of Dog Ticks, Dermacentor variabilis, and Deer Ticks, Ixodes scapularis, are also represented on BugGuide.

Letter 2 – Tick, possibly American Dog Tick

Is it a bug or a russian spy insect?
Thu, Apr 9, 2009 at 5:28 PM
Dear Bugman,
You’ve helped me once before in identifying a bug, a carpet beetle, in fact. I have a new mystery and I was wondering if you could help me once again. I have attached some photos. I found this critter on my wall outside of my bathroom in the basement of our house. I live in White Rock, British Columbia, not too far from the beach.

He was a little smaller than a dime, but not so small that I would consider him half the size of a dime. He looked as though he was encased in some sort of plastic that had holes in it for his legs and small part of his head to fit through. Once on his back inside the cup, he didn’t appear to be able to right himself (at least, he didn’t try while I was watching).

This was taken with my phone camera so the colouring is slightly off, but he was more of a true grey colour, almost even a slightly blue grey colour.

Any idea what this creature could be? Unfortunately, these are the only photos I have of him. I released him outside shortly after taking them.
I anxiously await your response.
Curiously yours,
White Rock, BC



Hi Cheryl,
This is a Tick, and it appears to be engorged with blood.  We suspect it might be an American Dog Tick, Dermacentor variabilis.

  There is a photo on BugGuide that closely resembles your specimen, and it was identified as an American Dog Tick after first being mistaken for a Deer Tick.  We would prefer that an Acarologist make the final call as to the species.


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Ticks

Related Posts

4 Comments. Leave new

  • what happens when the tick drops off i mean dose it die or goes off to find another dog and what happens to the dog? thank you

  • Pat Gonzales
    April 4, 2018 8:51 pm

    I just found this same bug on my couch where my chichuachua. Looks almost identical the photo sent by Cheryl. I live in the Los Angeles county in California. I have lived here all my life 50 yrs+. We don’t live out in the country but in the suburbs. All I have are flower beds and grass. What can I do to treat my lawn and flower beds to get rid of this?

  • Our Aussie had a Tick like the one posted by Cheryl. Are their eggs like black specks, like pepper?

  • Does the American Dog Tick, Dermacentor variabilis carry Lyme Disease?


Leave a Reply

Your email address will not be published. Required fields are marked *

Fill out this field
Fill out this field
Please enter a valid email address.
You need to agree with the terms to proceed