Does Dawn Dish Soap Kill Fleas on Pets? How It Works and When To Use It

You are in a state of mild panic when you notice the dreaded signs of fleas on your dog or cat—those tiny moving black dots down near the skin, flashing through your pet’s fur.  

Maybe you are also seeing small salt-and-pepper specks on the bedding—and worse yet, you have some bites around your ankles. Out of desperation, you grab the Dawn dish soap with one hand and your pets with the other as you head for the bathroom.  

But is this the best course of action when tackling fleas on pets?  

Does Dawn Dish Soap Kill Fleas?

The simple answer here is yes, Dawn dish soap does kill fleas. However, the full answer might not be as straightforward as it sounds.  

Dawn and many similar soaps affect the ability of the flea to float in water by changing the surface tension of the water, and the end result is that the flea sinks and drowns. Sounds wonderful, right? Not quite so fast.  

For each live flea you see, there are typically many more fleas in the environment in the form of eggs, pupae, and larvae. Adult fleas lay eggs, which hatch into wormlike creatures called larvae. The larvae spin cocoons around themselves as they prepare to become adult fleas—at this stage, they are pupae.  

All this means that most fleas are not found on your pet, but are actually found elsewhere in your house and yard. So although washing your pup might make you feel better and will definitely remove some of the live fleas from your pet, the second your pet is dry,  more fleas can jump back onto them.  

Dish soaps will drown live fleas on your pet but they cannot repel fleas or clear an infestation in your house, where most of the fleas are. This means bathing might be an OK strategy until you can implement a more complete flea control plan, but it isn’t a solution to a flea infestation. 

Does Dawn Dish Soap Eliminate Flea Infestations?

The unfortunate answer to this question is that Dawn will not clear your pets or your house of a flea infestation.  

Dish soaps can temporarily remove the live fleas from your pet, but there are many more fleas, eggs, pupae, and larvae scattered throughout your home and yard and even on other pets—none of which will be addressed by bathing your animals with Dawn.  

Once you have fleas in your home, it will take more steps than bathing to clear the infestation. 

Will Dawn Dish Soap Irritate My Pet’s Skin?

We’ve all seen the commercials of adorable ducklings being cleaned of oil using Dawn dish soap, meaning it is completely safe for animals, right? Actually, no, it isn’t.  

Dawn is extremely effective at doing its job—which is to strip oil from the fur or feathers of an animal (or off your dishes, for that matter). However, especially when used in this manner regularly, Dawn can leave your pet with a dry, brittle coat that is prone to irritation, inflammation, and infection.  

So if your pet gets uncommonly grimy and needs a quick bath, Dawn will likely be fine to use. However, for regular bathing, it’s better to use a gentle pet shampoo, which is less likely to irritate your pet’s skin.  

When dealing with an active flea infestation, you can use a flea shampoo in combination with a dog or cat flea medication as you deal with eliminating it. A pet shampoo formulated for fleas won’t rid fleas alone; it must be paired with medical treatment recommended by your veterinarian.  

It is always a good idea to keep a flea comb handy to check your pet for fleas. Combing the fur on high-infestation areas, such as the base of the tail or the belly, can help you quickly look for the early signs of a flea problem. With a good combing, you can easily spot the live fleas, their dark speck-like debris, and the tiny white eggs. 

When Should I Use Dawn Dish Soap on My Pet?

Dawn dish soap can occasionally be used to help bridge the gap between when you first find the fleas and when you can get your pet to a veterinarian for more definitive treatment.  

Because Dawn can dry out a pet’s fur and can be irritating to the skin, it’s generally recommended only for short-term use.  

Baths alone (whether with a dish soap or a product designed for flea control) will not clear an infestation. To get rid of the fleas, chances are you will need to pair a shampoo with flea medication or at least use a quality flea medication.