Kill Fleas with Dawn Dish Soap [DIY Dog Flea Treatment]

You’ve no doubt heard the stories of Dawn dish soap being used to clean animals after an oil spill. Needless to say, Dawn soap is effective at removing grease without harming humans or animals.

I know the feeling of eyeing products in your house and wondering if you can repurpose them. So, it might get you wondering—can you kill fleas with Dawn dish soap?

In short, yes, you can kill fleas with Dawn dish soap. However, it’s not the best flea-fighter out there.

I’ll help you understand how Dawn dish soap works on fleas and show you alternative options that’ll give your pet a better shot of getting—and staying—flea-free.

The Effectiveness of Dawn Dish Soap on Fleas

I won’t get too technical on you here, but there’s a scientific reason why Dawn dish soap is effective for animals during oil spills. It creates micelles, groups of soap molecules that grab fatty acids and prevent them from sticking to their host.

So, where do Dawn’s flea-killing powers come into play?

It has to do with a flea’s exoskeleton, which lets them float in water without dying. 

However, when you mix Dawn into the water, the soap creates a kind of surface tension that forces fleas to sink. In short, using Dawn on your pet kills fleas by drowning them. 

In fact, you’ll likely see some of those drowned fleas on your hands as you scrub your pet.

The Problem with Using Dawn Soap to Kill Fleas

Up until now, you’re understandably impressed with how Dawn soap kills fleas. However, we’re only considering adult fleas that are currently infesting your pet.

Unfortunately, these adult insects can live without your pet as a host for up to two weeks. That means they could be lurking in your dog’s bed (or yours) and other places in your home.

Needless to say, using Dawn soap to kill fleas is a temporary fix—if you scrub well, you can expect it to kill all the fleas on your pet. But the moment your pet encounters another flea, the infestation on their body will begin again.

Furthermore, it’s crucial to understand the flea’s life cycle. It goes like this:

  1. Egg
  2. Larva
  3. Pupa
  4. Adult

Although females lay eggs on their host, your pet will inevitably drop some of those eggs around your house or in the yard. 

So, using Dawn on your pet is like putting a Band-Aid; it temporarily fixes the problem instead of getting to the root of it. It also may cause skin irritations for your pet if they have sensitive skin, although Dawn soap effectively kills fleas even when you dilute it in water.

How to Use Dawn Soap to Bathe Your Pet

If you feel that bathing your pet in Dawn soap is the right temporary solution, fill a tub with warm water and get your pet damp, removing any dirt. Then follow the steps below:

  1. Apply dish soap to the water, using an amount that feels right according to how many fleas they have. 
  2. Scrub your pet well until you see dead fleas floating in the water. 
  3. Brush your pet’s coat while bathing them to encourage the fleas to detach from their skin.
  4. Rinse your pet well and dry them with a towel. 

Voila! Just like that, you should have a (temporarily) flea-free pet.

Topping Off a Dawn Bath With Vinegar

It may seem like an unattractive combination, and it is—if you choose to bathe your pet in Dawn soap and spray them with vinegar after, you stand a chance at repelling fleas for a short period.

Since the soap should take care of adult fleas, you don’t have to worry about getting the vinegar down to your pet’s skin. Instead, use a spray bottle and gently coat them in a light layer of 50% white vinegar and 50% water.

stop goldendoodle fleas
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When It’s a Good Idea to Use Dawn Soap On Dogs

Although Dawn soap isn’t the ideal way to permanently take care of your pet’s flea problem, there are a couple of situations when using it is a good idea.

  1. If you’re working with a flea-infested animal that’s too young to receive flea treatment.
  2. If you want to kick-start the flea killing in conjunction with giving your pet proper flea medication.

If you own a kitten, you can use Dawn soap to kill fleas until they’re 8 – 10 weeks old and at least 1.5 pounds. If you own a puppy, it’s suitable to use this soap until they’re 4 – 8 weeks old and at least two pounds.

After bathing your pet with Dawn soap, you can use a flea comb to physically pick any remaining (dead) fleas off your pet.

Better Flea Products Than Dawn Soap

Here’s the good news: Once your pet is old enough, you can (and should) keep them on a regular flea treatment that will prevent them from suffering from fleas. 

The advantage of using a flea formula instead of Dawn soap is that the medicine will kill fleas in all their life cycle stages. Plus, it’ll prevent your pet from getting fleas instead of only treating the problem once it happens.

Below are some of the products I recommend: (See our flea killing guide)

  • Advantage
  • Frontline Plus
  • Bravecto
  • Capstar
  • Seresto
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04/11/2023 10:08 am GMT
vet checking dog for fleas
A Vet checking a dog for fleas

What to Look for When Choosing a Flea Product

No two flea products are alike. So, below are some characteristics to consider when choosing the best option for your pet.

Administration Style

There are three primary ways to administer flea products: topical, oral, or collar.

Studies show that oral flea medicine is the most effective, at about a 99.9% rate. In contrast, topical medication hovers at roughly an 88% effective rate. 

On the other hand, collars are better suited if you have a pet that occasionally goes outdoors or has contact with other animals. 


Some flea medications require a monthly application. Others, like Bravecto, work for three months before you need to give your pet another tablet.

So, you should consider how much time you want to dedicate to keeping up with your pet’s flea treatment. If you’re the type of person who tends to miss items in their calendar, choosing a longer-lasting brand is likely a better fit for you.

What It Kills

Flea treatments will kill fleas. But some treatments also kill other external parasites, including ticks, lice, and mosquitos.

You should also ensure that the medication kills fleas at all four stages of their life cycle.

white maltipoo dog sitting on couch
A white adult Maltipoo sitting on a couch. Photo by Mitchell /CC BY

Keeping Your Pet Flea-Free

Unless your pet has sensitive skin, there technically isn’t anything wrong with using Dawn dish soap to get a jump-start on killing their flea infestation. However, you should always combine it with proper flea medication once they reach the right age and weight.

You can also consider using a flea shampoo instead of Dawn dish soap. Like Dawn, flea shampoo only solves the current issue, killing fleas on contact. Unlike Dawn, many flea shampoos recommend that you use it on pets 12 weeks and older. 

Regardless of the route you choose, the sooner you get working on eliminating fleas from your pet, the happier they’ll be.