Does Dawn Dish Soap Kill Fleas? What Experts Say
In This Article:
What Is Dawn Dish Soap? Does Dawn Dish Soap Kill Fleas? Is Dawn Safe to Use on Pets? How to Use Dawn Dish Soap for Fleas Alternatives to Dawn for Fleas
No one wants to see fleas on their cat or dog. In addition to being miserably itchy and irritated, flea-infested pets track flea eggs and larvae indoors. Fleas are very difficult to eliminate once they’re inside your house. With the risks of an indoor flea infestation, it’s no wonder that pet parents are searching for quick, at-home solutions as soon as they spot a flea.
Dawn dish soap comes up frequently in online discussions of at-home flea remedies, with proponents claiming that it kills fleas by drowning during bathing. Others say that Dawn is not an insecticide, so it shouldn’t be expected to kill fleas. Like most online controversies, the question of Dawn’s flea-killing power and its safety for use on animals gets a little complicated.
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What is Dawn dish soap?
Dawn dish soap consists of a combination of a dozen or more ingredients. It’s formulated to clean dishes by breaking down greasy residue. The ingredients vary from product to product, but primarily consist of the following types:
Surfactants, which help bind dirt and grease to allow them to be removed by water
Solvents, which help break down grease
Viscosity agents, which help thicken or thin the liquid
Cleaning agents
Stabilizers
Preservatives
pH adjusters
Fragrances
Antibacterials
Colorants
Does Dawn dish soap kill fleas?
All evidence of Dawn’s effectiveness at killing fleas is anecdotal. As far as I can tell, no one’s thought to test Dawn’s flea-killing power in a research setting. Seems like a reasonably straightforward experiment, but maybe grad students have better things to do. A few likely mechanisms for how Dawn dish soap works to get rid of fleas have been proposed.
How does Dawn dish soap work on fleas?
Drowning: The most commonly mentioned way that Dawn could kill fleas is by drowning them. The theory is that the soap helps break the surface tension of water, allowing fleas to sink into it and drown. This seems unlikely to work though, thanks to information from forensic entomologists. It turns out that fleas can drown, but it takes about 24 hours. Fleas can revive within an hour after being submerged for 12 hours. They can even recover from 18-20 hour periods under water, though it takes them 4-5 hours to come around. This makes Dawn killing fleas during a bath unlikely.
Dessication: Another way Dawn could kill fleas is by breaking down the waxy layer that protects their exoskeleton and airway. This would allow water into their airways and eventually cause drowning. Because fleas are so slow to drown, the time it would take for this to happen would be much longer than the average bath.
Physical removal: Although this method doesn’t kill the fleas right away, it’s the most likely way that Dawn could help you get adult fleas off your pet. Fleas become suspended in the soapy bubbles and are unable to jump or move to safety before being washed away. They may drown once they go down the drain or maybe they just go infest rats in the sewer. Either way, they’re no longer your problem.
Is Dawn safe to use on pets?
Although Dawn extensively promotes that their soap is used on wildlife to help clean up after oil spills, nowhere do they recommend that it be used to get rid of fleas on dogs and cats. In the case of oil contamination, the soap is being used for one of its primary dishwashing features: grease removal. The solvents in dish soap help break down grease, while the surfactants trap the oil and allow it to wash away when rinsed.
Dawn isn’t formulated to be a shampoo for cats and dogs. Remember, its job is to remove oil and grease. This includes the layer of oil that protects skin and prevents it from drying out. Using dish soap as a pet shampoo risks a dry, flaky coat. Some pets bathed regularly with dish soap can paradoxically develop greasy coats due to overproduction of oil in response to repeated skin injury.
Dawn isn’t necessarily toxic to dogs and cats, but it can cause some breathing difficulties and stomach upset if swallowed undiluted or licked while it’s lathered up. These issues tend to be mild in most pets, but it’s better to save your dog the humiliation and discomfort of having soap bubbles come out of their nose.
There are some scenarios where veterinarians may use dish soap in pets. It’s still occasionally recommended for bathing very young puppies and kittens, though this is less common than it used to be. Dish soap is included in many de-skunking recipes to help break down the oily skunk spray. A one-time bath using dish soap may also be recommended for cats exposed to spot-on flea productsopens in new tab that are toxic to them. Removal of the oily products and any skin oils carrying them can help reduce further absorption.
How to use Dawn dish soap for fleas
Because Dawn dish soap doesn’t have any special flea-killing effects and only helps to aid physical removal of fleas, it’s not recommended for flea control in pets. Other shampoos formulated for pets will lather up just as well and allow you to remove fleas without risking skin problems.
Alternatives to Dawn for fleas
The best flea control is prevention. Talk to your vet about which flea products work best in your area. Once-a-month flea medications have long been available for both dogs and cats, and newer products can last even longer. There are formulations available as oral medications, topical spot-ons, and collars to help get rid of active flea infestations and prevent fleas from setting up in your environment.
If your cat or dog manages to get some fleas on them, don’t panic. Talk to your veterinarian about what to do, but a wash with a shampoo made for dogs and cats is always a good first step. Really, any pet shampoo will work to physically remove fleas. Flea shampoos may help marginally by paralyzing the fleas, but a through bath and brushing should do the trick in most cases. Don’t be afraid to break out the flea comb to catch any stubborn fleas that weren’t rinsed away.
Bottom line
Despite being frequently mentioned as a way to kill fleas on cats and dogs, there’s no evidence that Dawn is an effective flea killer. It likely just physically removes fleas in the same way any other pet shampoo would, but has the downside of being harsh for skin. Unless advised otherwise by your vet, skip the dish soap and stick with a shampoo made for your pet.
References
Gennard, Dorothy. Forensic Entomology. Chichester, John Wiley & Sons, 2007.
Smartlabel. “Dawn Ultra Dish Soap Dishwashing Liquid Original, 19.4 fl oz.” https://smartlabel.pg.com/en-us/00037000535928.htmlopens in new tab. Nov. 23, 2025.
