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Dawn Dish Soap for Fleas: Does It Work?

Row of Dawn dish soap in store
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Dawn dish soap is often used to bathe animals with fleas, and you may have seen this product used by rescue workers to wash off grease from oil-soaked wildlife. The slogan, “it’s tough on grease yet gentle,” has been widely heard. 

This household product is easily accessible and cheap, but is Dawn dish soap for fleas an effective remedy for pet parents? 

Keep reading to learn about whether Dawn dish soap actually works for killing fleas and what pet parents should know before raiding the grocery store aisles. 

Does Dawn Kill Fleas?

The simple answer is yes, Dawn does kill adult fleas. However, it’s not recommended for pet flea prevention and treatment. In a pinch, it’s fine to use initially on a flea-infested animal to help remove fleas and wash off flea dirt, but it’s not an ideal long-term flea treatment because it doesn’t kill flea offspring or repel fleas.

Fleas are flat-bodied, six-legged wingless parasites that are about an eighth of an inch in size and reddish-brown or black in color. The most common signs of a flea infestation are scratching, biting, skin wounds or hair/fur loss, and small red bumps or flaking skin (if infection occurs). 

Fleas are visible to the naked eye and get around by jumping, reaching as high as 48 centimeters. This is important to keep in mind because when you use Dawn dish soap (or any other similar dish soap), it only physically removes the adult fleas on the pet. It does not address the underlying problem of fleas in the pet’s environment, including flea eggs and larvae, which allows for prompt reinfestation of your pet.

“It lifts grease from the skin, helping sweep up the fleas, wash them off, and drown them,” says Dr. Julie Sanders, director of operations at Heart + Paw. However, it doesn’t get rid of fleas entirely because, as soon as your pet is out of the sink/tub, “new fleas can jump on and survive.” 

Will Any Dish Soap Kill Fleas?

“Dawn has no special properties to kill fleas. Any shampoo or detergent acts about the same in physical removal [of fleas],” says Dr. Sanders. However, she stresses that there are “gentler shampoos that would be just as effective in temporary removal of adult fleas.” 

Consult with your veterinarian about the safest and most effective method of flea control for your pet, depending on their age and health status. 

If you are going to use Dawn, Dr. Sanders recommends sticking to the original formula and avoiding versions with heavy scents and “oxy” additives. “Irritation from detergents tends to be greater from the “oxy” formulas that contain forms of peroxide,” she adds. “The additional oxidizing action of peroxide can cause additional irritation and be especially harsh on the skin.” 

Diluted Dawn soap (mixed with water), may be used to kill fleas on very young puppies or kittens who are not old enough for vet-recommended flea preventatives. However, there are more skin-friendly options available on the market that are specifically made for companion animals. 

Is Dawn Dish Soap Safe for Dogs and Cats?

Foamy dish soap

According to Brian Taylor, professional groomer of DogFatherofHarlem and owner of Harlem Doggie Day Spa in New York City, if a pet is infested with fleas, the skin is already irritated. Although Dawn dish soap isn’t toxic, the chemicals in it can “cause further damage such as drying of the skin, dulling the coat, and literally stripping the natural oils that a pet needs”.

“I personally advise against using Dawn detergent or any soap not intended for a pet when possible,” adds Taylor. 

Liquid soap can get into places such as eyes and nasal passages and can also be inhaled or ingested, which can cause problems, ranging from mild irritation to pneumonia, says Dr. Sanders. “Ingestion can cause nausea and vomiting. Accidental inhalation (which can happen when bathing a wiggly pet) can destroy the sensitive lining of the lungs and predispose pets to pneumonia.” 

How to Use Dawn to Kill Fleas

If you are looking for a one-time or fast-acting solution to kill adult fleas that are on your dog or cat, Taylor recommends the following steps: 

  • Combine 1 quart water, 1 cup white vinegar/apple vinegar and 1 cup baby shampoo or Dawn/other liquid soap. 
  • Use this mixture to bathe your dog or cat in the tub, but do not pour soap directly into a bathtub filled with water. Soap can irritate your pet’s eyes. 
  • Do not use this mixture anywhere near the pet’s head or eyes. 

Why You Shouldn’t Rely on Dawn for Flea Infestations

To eliminate fleas successfully, treatment needs to focus on breaking their life cycle. “Adult fleas are only 5 percent of an active flea infestation,” explains Dr. Sanders. “ 95 percent of a flea infestation is in the juvenile stages in the environment.” 

According to Dr. Sanders, this means that for every single adult flea you see being drowned through shampooing, there are around 95 eggs, pupae, and/or larvae in the environment, including in the carpet, dog beds, grass, tile cracks, or hardwood floors. For every female flea, expect at least 40 eggs per day that are on the animal’s skin, which then fall off into the surroundings. These juveniles will quickly develop and can jump onto your pet and re-infect them.

Dawn dish soap doesn’t clean the surroundings or repel fleas. “By the time we notice a single flea on a dog, the infestation has been there for about two weeks. Since cats are fastidious groomers, they can hide the infestation for even longer,” says Dr. Sanders. 

Best Methods for Killing and Preventing Fleas

Person bathing dog at home

When you notice fleas on your pet or suspect that they exist in your house, here are some methods to prevent an infestation. 


Your pet’s coat provides the perfect warm habitat for external parasites like fleas to thrive. “They like to hangout underneath tangled and matted hair/fur making it very uncomfortable for the pet because they are being bitten by these parasites nesting and traveling along the skin,” says Taylor. 

He recommends regular grooming to prevent matted or tangled fur and more importantly to locate fleas or ticks. 


In between grooming sessions, brush your pet regularly and thoroughly, by working your way to the scalp and detangling from there, recommends Taylor. “If there is knotting, a comb can assist with the knots and a gentle detangling spray can help soften the hair/fur. If there is serious knotting, you will need a groomer because this can be a painful process.” Add using a flea comb (a finely-spaced comb), to the routine to get fleas, flea dirt, and even eggs off your pets. 

Flea and Tick Preventatives

Preventing flea infestations is much easier and more cost-effective than having to treat an infestation once it happens. There are several flea preventatives on the market (for dogs and cats) that are oral and topical. A more cost-effective preventative is the flea collar, which can be fitted around your pet’s neck, though the oral and topical medications may work better for many cats. There are also oral medications (nitenpyram) that can be given to kill the adult fleas, but these should be used in conjunction with preventatives and environmental management. Keep in mind that you will need to treat all in-contact pets in the home. 

Deep Cleaning

Keep your pet’s surroundings and yard clean to prevent flea growth. Vacuum regularly with a machine with good suction to remove fleas of all stages from the environment. Wash rugs, bed covers, and upholstery covers. Clean dog blankets using the hottest setting in the washing machine.

When in doubt, you can always enlist the help of your veterinarian and pet groomer to help you combat these pesky insects.

Editorial credit: jadimages / Shutterstock.com