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Fleas

Ctenocephalides felis and C. canis
Updated Oct 04, 2022
 
1

Make a Positive Identification

Cat fleas (Ctenocephalides felis) and dog fleas (C. canis) are common in our region. If your pet is scratching or chewing its body, look for fleas in the hair or fur.

In the Pacific Northwest, flea activity increases in spring and continues into fall. However, fleas survive year-round in our region.

Fleas
Species: Fleas
Closeup photo of a flea

pxChrome, iStock

Adult fleas are roughly 1/8-inch long, dark brown, and wingless insects.

Species: Fleas
Ctenocephalides adult feeding on skin

Acarologiste, CC BY-SA 4.0, via Wikimedia Commons

Adult fleas bite and eat the blood of their hosts as shown in the illustration. Hosts include dogs, cats, and other pets. Fleas also infect people.

Species: Fleas
Cat flea eggs

© Ken Gray Insect Image Collection

The tiny white, smooth, oval eggs fall off the host animal and survive in the carpet, furniture, and pet bedding.

Species: Fleas
Flea larvae

Pest and Diseases Image Library, Bugwood.org

The larvae feed on dried blood provided by the adult fleas or organic debris.

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LOOK FOR SIGNS OF FLEAS
Species: Feas
Cat scratching its shoulder

Sony_moon, iStock

Observe your pet to see if it is scratching and chewing. Repeated scratching and chewing are signs of a potential flea infestation.

Species: Fleas
White box highlighting a flea on dog

kozorog, iStock

If you see your pet scratching or chewing, look closely at the coat for fleas. Check on the belly and behind the ears. The white box in the photo highlights a flea on a dog.

Understand Fleas’ Life Cycle
Species: Fleas
Diagram of dog flea life cycle including definitive host (dog), flea eggs, flea larva, flea pupa, and flea adult
Blueringmedia, iStock

The diagram shows the life cycle of fleas.

Female fleas lay hundreds of eggs in their lifetime. The tiny white, smooth, oval eggs fall off the host animal and survive in the carpet, furniture, and pet bedding.

The eggs hatch and larvae emerge in 2–14 days. Larvae crawl and feed on the blood of the host for 1–2 weeks. The larvae then pupate.

Adult fleas emerge from the cocoon in roughly 1–4 weeks.

The adults may remain in the cocoon longer if conditions are unfavorable; for example, if an infested house becomes uninhabited by a pet.

Look-Alike: Ticks
Species: Ticks
White box highlighting a tick on a dog

CasarsaGuru, iStock

  • The white box in the photo highlights a tick in dog fur.
  • Ticks are arthropods that attach themselves to people, pets, and other animals. They feed on blood.
  • Ticks can spread diseases such as Lyme disease to people.
  • Dogs are susceptible to tick bites and tick-borne diseases.
  • Cats are sensitive to certain tick control chemicals.
Different risks or methods

Talk to your veterinarian about medication for ticks for your pets.

Learn more about Ticks  (Centers for Disease Control and Prevention.

 
2

Fleas Benefits

  • Fleas are annoying insects. They don’t have any benefit for people, pets, or the environment.
 

Fleas Risks

  • Flea bites are itchy and irritating. Some people and pets suffer from flea-bite allergic reactions.
  • Fleas sometimes transmit diseases and internal parasites (tapeworms) that can harm you and your pet.
  • Getting rid of a flea infestation requires treating your pet. You also have to clean indoor and outdoor areas where your pet spends time.

 

Risk Card
Does it cause harm?
Adults & Children
High
Property
High
Pets
High
Annoyance
High
Environment
None
Action Highly Recommended
 
3

Take Action

Take action right away to control fleas and create a long-term plan to manage them.

Do I need to take action?

It is critical that you act to control a flea infestation. A flea problem will not go away without intervention. Use preventive measures for best results.

What if I do nothing?
Flea infestations get worse and harder to manage the longer you wait to take action.

NEED HELP?

Consider a licensed pest control company. Learn How to Hire a Pest Control Company.
Your local Extension Specialist in Oregon  and other states  can suggest other methods.

 
4
Solutions for Fleas
  • The first step is prevention. Talk with your veterinarian to develop a monthly flea medication treatment for your pet. Inspect your pet regularly. Develop a long-term flea control plan.
  • The second step is sanitation. If you find fleas on your pet or in your home, wash your pet’s bedding. Thoroughly clean and vacuum surfaces. Focus on carpets and areas where your pet spends time.
  • The third step is treatment. Treat your pet and home with products that contain insect growth regulators. Read and understand product labels before you use them. Follow the instructions.
  • The last step is ongoing monitoring. Inspect your pet and your pet’s bedding daily for signs of fleas. Vacuum regularly. Re-treat as needed, following the product label instructions.

Jump To

Method Does it work? Is it safe? Recommendation
A
Combing, Shampooing & Vacuuming
Effective
Low risk
Recommended
B
Flea Medication from Vet
Very effective
Moderate risk
Recommended
C
Flea Products from Stores
Somewhat effective
Moderate risk
Use if Necessary
D
Insect-Killing Foggers
Does not work
High risk
Not Recommended
E
If Using Insecticides, Protect Yourself & Minimize Risks
F
Prevent Fleas
 
A

Combing, Shampooing & Vacuuming

Non-Chemical Method

K_Thalhofer, iStock

Combing, Shampooing & Vacuuming

Recommended

These steps are required to get rid of a flea infestation in your home.

Does it work?
Effective

Combined with chemical methods, vacuuming your home and combing and shampooing your pet effectively gets rid of a flea infestation.
How much effort?
High effort

These required steps require significant effort
What's the risk?
Low risk
Possible risk of exposure or harm from chemicals
NONE
Person using flea comb on pet

K_Thalhofer, iStock

  • Use a flea comb to remove fleas from your pet.
  • Look for adult fleas and dark flecks of dried blood. Put fleas caught in the comb in soapy water.
  • Comb your pet regularly with a flea comb to monitor for fleas.
Family washing dog outdoors

THEPALMER ,iStock

  • Washing your pet with shampoo drowns fleas and dries out surviving fleas.
  • Shampooing removes the skin flakes and dried blood that feed developing fleas.
Vacuum wand on pet bed

Weston Miller, Oregon State University

  • Vacuum carpets, rugs, upholstered furniture, and pet’s bedding regularly.
  • Vacuum under pet bedding and furniture where your pet spends time.
  • Also, choose launderable pet bedding. Launder pet bedding weekly with hot water.
 
B

Flea Medication from Your Veterinarian

Chemical Method: Use with caution

Tashi-Delek, iStock

Flea Medication from Your Veterinarian

Recommended

Flea medications are applied directly to your pet. They are key for long-term flea management.

Does it work?
Very effective

Highly effective. Easy to use. Make flea control much easier than without using them. Provide long-term flea control.
How much effort?
Low effort

Medication is edible or applied to the pet’s skin.
What's the risk?
Moderate risk

Insecticides come with real risks. ALWAYS read the entire label front to back. Review instructions even for brands you know.
Possible risk of exposure or harm from chemicals
Using medication includes some amount of risk.

Follow the instructions from your veterinarian to minimize risks.

Flea medications for your pet are convenient to apply. They are very effective. Using prescription flea medication makes the whole process of flea control easier compared with not using them.

Chewable flea medication

Weston Miller, Oregon State University

  • Talk to your veterinarian about flea medication for your pet.
  • The medication can be given monthly as a chewable treat or food additive.
  • This medication is also available every 6 months as an injection.
  • Example active ingredients include lufenuron.
Worker applying topical flea medication to dog

Mustafagull, iStock

  • Your veterinarian can also prescribe flea treatment to apply monthly to your pet’s skin.
  • Apply topical treatments on your pet’s neck where it is out of the animal’s reach.
  • Products you feed your pets are a better choice for pets that swim or bathe regularly.
  • Examples of active ingredients include imidacloprid and fipronil.
 
C

Flea Products from Stores

Chemical Method: Use with caution

Weston Miller, Oregon State University

Flea Products from Stores

Use if Necessary

Flea control products with active ingredients include methoprene and pyriproxyfen are available in shampoos and dusts for your pet and products for use indoors.

Does it work?
Somewhat effective

Combined with vacuuming and combing, flea-control products available from stores get rid of a population of fleas. They DON’T ensure long-term flea control.
How much effort?
High effort
What's the risk?
Moderate risk

Insecticides come with real risks. ALWAYS read the entire label front to back. Review instructions even for brands you know.
Possible risk of exposure or harm from chemicals
Using insecticides includes some amount of risk. The lowest risk comes with using alternative methods.

You may be exposed to an insecticide if you:

  • Get it on your skin
  • Breathe it in
  • Eat or smoke afterward without washing hands
  • Touch surfaces that are wet with spray (you, pets, or children)

Follow directions closely to reduce risk.
  • The most effective flea-control products for your pet include Insect Growth Regulators (IGRs). These ingredients disrupt the flea life cycles. IGR active ingredients include methoprene and pyriproxyfen. They are available in shampoos and dusts for your pet and products for use indoors.
  • Products that contain borate are also available for flea control on indoor carpeting. Flea larvae in carpets are killed by the product. Adult fleas are not harmed. Borate-containing carpet shampoo products are also available.
  • Read and follow the label instructions for best results.
Flea products for indoor use

Weston Miller, Oregon State University

Products for Indoor Use

  • Products available for indoor use include IGRs and sprays based on citrus oil that contain active ingredients limonene or linalool.
  • These spray and powder products are applied to rugs, carpeting, and pet bedding. They kill only fleas that are contacted by spray or powder. Follow-up treatments are necessary.
  • Keep vacuuming the area for several weeks as the products disrupt the flea life cycle. If you still see fleas after 2 weeks, re-treat the area.
Flea products to apply to pet

Weston Miller, Oregon State University

Products Applied to Pets

  • The photo shows examples of products with IGR and other ingredients.
  • These products are applied directly to pets.
  • They come in shampoos and dusts.
Cat with flea collar

KrisCole, iStock

  • Flea collars contain insect growth regulators and other insecticides. The collar releases the ingredients that spread on the animal’s coat.
  • Read and follow the instructions for flea collars. They are designed to stay on your pet for 6 days only or less.
  • There is little information about the effectiveness of flea collars.
Some products applied to a dog’s skin contain active ingredients permethrin and amitraz, which should NOT be applied to cats. If you have both dogs and cats in your household, be aware that using products with permethrin or amitraz can harm your cats. Talk to your veterinarian before using products that contain these ingredients.
 
D

Insect-Killing Foggers

Not Recommended

Weston Miller, Oregon State University

Insect-Killing Foggers

Not Recommended

Insect-killing fogger products don’t effectively control crawling insects such as fleas.

Does it work?
Does not work
  • Research shows that insect-killing fogger products don’t effectively control fleas.
  • The insecticide mist kills insects that it contacts directly. Fleas hide in crevices and folds of fabrics that the mist can’t penetrate.
How much effort?
Moderate effort
What's the risk?
High risk
  • Fogger products pose risks. Some foggers may be flammable. Insecticide residue left on counters, bedding, and fabric is a problem. You must wash these items before you use the area that’s been fogged.
  • See Bug Bombs Dangerous and Not Always Effective  (University of California ANR).
Possible risk of exposure or harm from chemicals
Using insecticides includes some amount of risk. The lowest risk comes with using alternative methods.

You may be exposed to an insecticide if you:

  • Get it on your skin
  • Breathe it in
  • Eat or smoke afterward without washing hands
  • Touch surfaces that are wet with spray (you, pets, or children)

Follow directions closely to reduce risk.
 

If Using Insecticides, Protect Yourself & Minimize Risks

Chemical Method: Use with Caution
Dog and cat in home

chendongshan, iStock

Why Is It Important to Read Insecticide Labels?

  • They have detailed information on how to use the product correctly and legally.
  • They contain information on potential hazards of the product.
  • They provide instructions you should follow for poisonings and spills.

Key Safety Tips for Insecticides

  • Read the entire label front to back. Follow the instructions.
  • Review the instructions even for brands you know.
  • Only apply the product where the label says it may be applied.

The Label is the Law

ALWAYS read the label before using insecticide products. The label is a legal document that provides information on how to safely use the insecticide. This helps avoid harm to human health and the environment. Using an insecticide in off-label ways is illegal. It can result in legal enforcement actions.

READ THE LABEL & Follow Instructions
It has instructions to protect you and the environment.

  • Labels are different for every product and they often change over time.
  • Use a magnifying glass.
  • Pay attention to CAUTION, WARNING, and DANGER statements.
  • Pay attention to the PRECAUTIONARY STATEMENTS.
  • The law states you must read and follow insecticide instructions.

Protect Yourself
Eye, skin & lung irritants

  • Wear gloves, safety glasses, a long-sleeve shirt, pants, socks, and shoes.
  • Avoid contact with eyes, skin, or clothing.
  • Wash hands after mixing or applying, and before eating or smoking.

Protect Children & Pets
Keep out of the reach of children.

  • Keep children and pets away from the application area.
  • Remove toys and pet dishes from the area before applying insecticides. Wait until spray has dried or dust has settled.

Storage & Disposal

  • Store out of the reach of children and pets.
  • Store in a cool and dry place.
  • Never pour down any drain.
  • If you mix too much, apply it rather than storing it.
  • Don’t put pesticide containers in the trash unless instructed by the label.
  • Take unused insecticides to a hazardous waste facility.

Call  1-800-CLEANUP (1-800-253-2687) to find out where to dispose of pesticides.

For the Portland metro region in Oregon, contact Metro’s Recycling Information. Call  503-234-3000, email   or visit Metro’s website  

More about:

About Using Pesticides on School Grounds in Oregon

If using pesticides on school grounds, there are special rules in Oregon. See School Integrated Pest Management  (Oregon Department of Agriculture).

NEED HELP?

The National Pesticide Information Center (NPIC)  can answer questions about pest control chemicals.
 1-800-858-7378 or npic@ace.orst.edu  

Consider using a licensed pest or weed control company. Learn How to Hire a Pest Control Company.

Your local Extension Specialist in Oregon  and other states  can suggest other methods.

 

Prevent Fleas

Veterinarian with dog

Tashi-Delek, iStock

Work with Your Veterinarian

The most important flea-prevention action you can take is to develop a flea control plan with your veterinarian.

Other Flea-Prevention Methods
  • Don’t wait until fleas become a problem.
  • Regularly clean your home and focus on where your pet spends a lot of time. Inspect your pet for fleas, and carefully follow the label directions of whichever treatment product you use.
  • If you have a flea infestation, focus control efforts on the heavily infested areas that are often where pets spend the most time.
  • Wash your pet’s bedding and movable rugs.
  • Vacuum attached rugs and upholstered furniture. Vacuum beneath cushions and in cracks and crevices.
  • Vacuum carpets beneath furniture.
  • Spray all carpets with a treatment product that contains insecticide and an insect growth regulator.
  • Vacuum daily for 10–14 days weeks to remove adult fleas that continue to emerge.
  • Place the vacuum bag or canister in a plastic bag and discard outside in the trash.
  • When you are controlling fleas in your home, also focus on treating your pet.
  • Use a skin-applied or an oral flea treatment recommended by your veterinarian or purchased at a pet supply store.
SEE OTHER COMMON PACIFIC NORTHWEST INSECTS

Content provided by editor Weston Miller and writer J. Jeremiah Mann. Pesticide safety information edited by Kaci Buhl.

 Reviewed by OSU Department of Horticulture.

Photo of Weston Miller

Weston Miller

Project Founder and Content Writer

Weston Miller served as Community and Urban Horticulture faculty for Oregon State University Extension Service for Clackamas, Multnomah, and Washington Counties. Weston is an author for content for this website. He developed funding partnerships with Portland area agencies to initiate and build out the Solve Pest Problems website focused on this goals:

J. Jeremiah Mann

J. Jeremiah Mann

J. Jeremiah Mann completed a Physical Science undergraduate degree at Humboldt State University, and M.S, Ph.D focusing on plant science topics at UC Davis. He went on to work for the Natural Resources Conservation Service and in a leadership position serving a private agricultural technology company. He currently lives in Sacramento California where he consults on pest and property management topics.

Photo of Kaci Buhl

Kaci Buhl

At the state level, I lead the Pesticide Safety Education Program (PSEP). The program hosts live recertification events around the state, serving over 1,000 licensed pesticide applicators each year. We also produce web-based training modules and license-preparation study manuals. Special training for unlicensed pesticide applicators is also available through a grant from the USDA Specialty Crop Block Grant Program. The PSEP at OSU works closely with the Oregon Department of Agriculture's Pesticides Division.

FLEA REFERENCES

Public health pests — Flea  
PNW insect Management Handbook

Fleas  
University of California IPM