What to Do When Your Dog Has Fleas

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Dog on grass looking up at camera
Dog On Grass Looking Up At Camera

Getting rid of fleas on pets and in the home requires a multi-pronged, patient approach. Your veterinarian is the best resource for specific information about your pet,* but here are some quick tips to get started in the fight against fleas.

*Your vet knows about your pet's overall health, any concerns with concurrent medications, and what works best for the fleas seen in your local environs.

Cats and Dogs

Some animals are more noticeably bothered by fleas - scratching, chewing, grooming excessively - and some pets do not seem to notice. Animals who are allergic to flea bites are often very bothered; with red inflamed skin and lots of chewing and licking.

If you have multiple pets, it is important to treat all pets, even if only one flea is found on one pet.

focus photography of an adult Labrador Retriever
focus photography of an adult Labrador Retriever

Flea treatments that are safe for dogs may be very toxic to cats. In some cases, toxic to cats just from close proximity or mutual grooming. All flea treatments (shampoos, sprays, spot- ons) should be used only on the intended species at the correct dose.

More is not better - ignoring label directions may kill your pet.


It may be tempting to wash your pet with a flea shampoo and kill fleas as quickly as possible, but speak to your veterinarian first. If you elect to use a spot-on treatment for your pet, a flea shampoo may strip your pet's skin and coat of the natural oils that are necessary for the treatment to work effectively.

Some spot-on treatments are waterproof after 48 hours, so a bath (or swimming) is OK. In this case, regular shampoo (not an insecticide flea shampoo) may be helpful in removing flea dirt and debris and soothing irritated skin.

black dog sitting on brown grass
black dog sitting on brown grass

In some cases, a flea bath is called for. Be sure to wait a 1 to 3 days after the bath to allow for complete drying of the coat and time for natural oils to replenish.

Shampooing dog
Shampooing Dog

Spot-On and Oral Treatments

There are many brands and types of treatments to choose from. Your veterinarian is your best resource for discussing the specific needs of your household.

Some points to consider when choosing a spot-on flea control:

  • The degree of a flea problem in the home
  • Type of pets (only dogs, only cats, mixed dog, and cat household)
  • Level of contact between pets
  • Lifestyle - does the pet swim or receive regular baths?
  • Will travel to flea - heavy climates happen during treatment phase?
  • Other medications or health concerns the pet has

Flea Combs and Grooming

Whatever the main method of flea control, daily grooming of your pet not only helps to remove fleas and flea dirt (which is food for flea larvae), it helps you monitor how effective your flea control and eradication program is.

shallow focus photography of dog lying beside grass
shallow focus photography of dog lying beside grass

Flea combs are fine-toothed combs useful for removing fleas and flea dirt from the pet. Dipping the flea comb in a solution of mild soapy water will help trap any fleas brushed out, as they move and jump quickly.

It is important to note that seeing fleas hours or days after a treatment application may not indicate failure. Eradication efforts take time. Eggs, pupae, and larvae out in the environment will hatch and jump on the pet for a blood meal. In time, the numbers of fleas and amount of flea dirt should lessen and ultimately disappear.

Home Treatment

No flea control problem is complete without addressing the home environment. Adult fleas live primarily on the host, but the eggs, larvae, and pupae are out there on the carpet, pet bedding, and furniture.


- The first defense against fleas in the home is daily vacuuming of carpets, under furniture, and on furniture.

grey and white miniature schnauzer on grey concrete fence
grey and white miniature schnauzer on grey concrete fence

This helps to remove the various stages of the flea life cycle as well as flea dirt and other food for flea larvae. Additionally, the mechanical action and vibration of vacuuming stimulate the flea pupae to emerge quicker, shortening the life cycle, making control easier.

Dispose of the vacuum bag or canister contents immediately to avoid reinfestation from contents vacuumed up.


- Fleas in the environment are heaviest where pets sleep. Frequent (weekly, at least) washing of pet bedding in hot water helps to reduce the flea population.


- Similar to spot-on treatments for pets, there is a wide range of products to choose from for the home, in the form of sprays and foggers. Caution is advised when pets are present. Animals should be removed from the area during the application until dry.

short-coated gray dog running on green grass field
short-coated gray dog running on green grass field
grayscale photography of French bulldog
grayscale photography of French bulldog

Some treatments, such as food grade diatomaceous earth, or DE (not the DE used for pools), work by mechanically 'slicing' the flea, they are not a chemical insecticide. Caution is advised when applying DE, as it is a fine talc. A dust mask should be worn during application to avoid breathing it in.

Quick Flea Facts

There are many species of fleas that parasitize animals. The cat flea, Ctenocephalides felis, is the most common flea found on both cats and dogs in the US.

Here are some quick facts about this flea:

  • Adult cat fleas range in size from 1-3 mm, they are reddish brown to dark brown in color.
  • The flat, bristly body of the flea allows for quick, hard-to-get movement through pet hair.
  • Large hind legs enable this flea to move quickly and jump high, on the pet and off.
  • Fleas have a 4-stage life cycle: egg, larva, pupa, adult.
  • The cat flea is unique in that it lives primarily on the host as an adult. The other life stages are most commonly found in carpets, bedding, and furniture.
  • Fleas feed on the blood of the host (pets, people).
  • Flea excrement, known as flea dirt is what the flea larvae feed on. Larvae also feed on other organic matter found in pet bedding and carpets, such as dead skin and food particles.
  • Fleas thrive in humid environments with moderate to warm temperatures (least 75 percent and the temperature is 70 to 90 F)1.
  • The length of the flea life cycle varies greatly with the environment (humidity, temperature), but averages 30-75 days. 1
  • Fleas may transmit diseases, such as Bartonella henselae (cat-scratch disease) and plague.

1-Source: University of Florida Entomology And Nematology Department