HomeResource CenterWhat Kills Fleas Instantly On Dogs

6 min read

How to Get Rid of Fleas on Dogs & What Kills Fleas Instantly

Written by

Jocelyn Stange, MA

Fleas are annoying and stressful. They can irritate pets with flea allergies, transmit disease, and cause a host of other problems for your pets.

On top of that, finding fleas on dogs naturally makes us feel dirty and discouraged. But don't worry, fleas are a common problem among pet owners. With the right approach, you can deal with fleas.

Many pet parents take a wait-and-see approach to flea control, treating only if they notice itchiness or fleas. But, if you have an active flea problem you need to know what kills fleas on dogs instantly — and how to get rid of fleas on dogs for good.

Keep reading to find out:

  • What kills fleas instantly on dogs
  • How to get rid of fleas on dogs
  • How to find the most effective flea treatment
  • Types of flea treatments for dogs
CycleKiller - Build Your Kit

What kills fleas instantly on dogs#

The safest and most commonly used product to kill fleas instantly on dogs is Nitenpyram — an oral fast-acting chewable tablet commonly known as Capstar®. Once administered it will kill fleas within 30 minutes and lasts up to 48 hours.

What is Nitenpyram

The closest pet owners can get to immediate flea relief is by treating their pets with Nitenpyram. Common brands of Nitenpyram include Capstar® and Bestguard® which can be purchased through a veterinarian, online, and over the counter. This is the best flea killer for dogs.


Nitenpyram kills fleas on dogs quickly. But, be sure to pair it with a complementary preventative product to kill fleas at every life cycle stage (i.e., flea eggs, pupae, and larvae).

Does Dawn dish soap kill fleas on dogs

Many articles talk about the effects of Dawn in getting rid of dog fleas. Giving your dog a bath with dish soap can help get rid of adult fleas from your dog's coat. But, there are some precautions to be aware of with Dawn.

  • If you've treated your dog with a topical flea and tick treatment, Dawn will remove the solution and strip the oil in your dog's skin which allows the treatment to spread and work.
  • If you have an active flea problem, bathing your dog will only remove flea dirt, flea eggs, and adult fleas on your dog. You will also need to treat your home.
CycleKiller - Build Your Kit

How to get rid of fleas on dogs

Flea control starts with killing fleas at the source to stop the flea life cycle. Fast-acting oral treatments work right away but aren't great for long-term use.

Treat fleas (and prevent them from coming back) by following these steps in your home, yard, and on your pets.

1. Gather the right tools.

Before tackling any pet health problem you want to be prepared. With the right tools, you can confidently address your flea issue. Here are a few items to keep on hand:

  • A flea comb
  • A bowl of soap and water
  • A clean, white paper towel (to see flea dirt)
  • Gloves
  • Household flea spray
  • Flea and tick treatment for pets

2. Find a good location.

Dead fleas and flea droppings will fall off your dog as you treat them so having a drain is helpful. Consider removing fleas on your dog outdoors or in a shower or tub.

This makes it easier to access water and clean up afterward. Bathing your pet can be helpful, but make sure you wait at least 48 hours before and after applying flea treatment.

3. Remove all visible adult fleas, flea eggs, and flea dirt with a flea comb.

Use your flea comb or fingers to part your dog’s coat and remove flea dirt and adult fleas. Flea combs glide through your dog's coat and pick up adult fleas and flea poop along the way.

Once removed, quickly put the comb in the soapy water. This kills fleas and flea larvae instantly. Continue working through your dog's fur and check all areas where dog fleas like to hide.

4. Groom your dog often.

In addition to supporting your pet's health, grooming is a great way to prevent and kill fleas on your dog. You can also bathe your dog in hot soapy water with Dawn to kill adult fleas, but this is not a good long-term solution. When you bathe your pet, it’s better to use pet shampoo.

If you're dealing with a flea infestation, a bath can help remove a good portion of the flea population. After bathing, be sure to treat any areas of flea allergy dermatitis on your dog’s skin.

5. Change your dog's bedding regularly.

During the flea life cycle, the adult female flea lays eggs which drop onto areas where your pet resides. To remove these pesky parasites at all flea life stages wash your pet's belongings in hot, soapy water.

And don't stop at your dog's things — soak any cushion covers, blankets, and bedding your dog spends time on. Even better, dry clean if you can.

6. Vacuum carpets and floors.

The flea life cycle lasts about 14 days. So, even if you've treated your dog for fleas, they could continue to develop and prolong your flea infestation. Plus, fleas can jump up to 200x their body length.

If your dog is around other pets who are unprotected, they could be at risk of re-infestation. Vacuum anywhere your dog likes to sleep and immediately discard the contents of the bag or canister.


Place the contents in soapy water, this kills fleas instantly.

7. Safeguard your home with pet-friendly flea control.

To keep your pet from being re-infested with fleas, you need to treat the inside of your home with pesticide. Spray your home throughout the year — especially during flea season — to keep fleas away.

Look for a household spray that contains an Insect Growth Regulator (IGR) and adulticides. These ingredients kill fleas and prevent flea eggs from developing. Which helps avoid a future flea infestation.

Do your research and read the instructions before treating your home. Most are safe to use around pets and humans and dry in a few hours.

8. Keep your yard tidy.

A well-kept yard is a great way to keep all types of bugs and critters out. And fleas love dark, moist environments. So, remove extra yard waste and standing water to provide more sunshine to your yard.

  • Remove standing water
  • Trim back plants, bushes, shrubs, and trees
  • Cut the grass short
  • Clear out extra dirt, rocks, or leaves

9. Meet with your vet for guidance.

Your vet is a great resource to help you:

  • Determine the right type of flea treatment
  • Help them stay up-to-date on vaccines
  • Monitor their health and conditions

At your annual dog check-up, ask your vet to look for any parasites, worms, and infections. Even if you haven’t found an active infestation, your dog could have an infection from a flea bite.

10. Choose the right treatment for your pet.

Always check with your vet about using specific products on your pets. There are some natural ways to kill fleas, like home remedies. But others, like tea tree oil, apple cider vinegar, and baking soda, may be harmful.

Talk to your vet about what flea treatment is right for your pet. And, do your research to find the safest and most effective medication or natural flea killer for dogs.

CycleKiller - Build Your Kit

How to find the most effective flea treatment

So, how do you find the most effective product for your pet? Here are some important traits to look for in your dog’s flea treatment.

1. Make sure they have key active ingredients.#

First, find a medication that will kill fleas safely and effectively. Flea medications can have side effects or neurological adverse reactions, and not every product is appropriate for keeping every pet healthy.

But, how does flea medicine work? The best flea treatment for dogs includes active ingredients that effectively kill and repel fleas and ticks.

Active ingredients that kill and act as flea repellent for dogs and cats

Kills fleas (all flea life stages)
Kills ticks
Kills mosquitoes
Kills flea eggs & larvae
Repels pests
Safe for cats

2. Look for flea treatments that last.#

Dealing with a flea infestation can feel overwhelming, but it is possible to get rid of fleas for good. From natural remedies like coconut oil to using a flea collar or shampoo — there are a lot of options to choose from.

Any brand that has a money-back guarantee for flea removal should be evaluated with caution. There isn't a quick solution for taking care of flea eggs, dirt, and more on your dog. But, most preventative treatments last about 30 days.

3. Be consistent about your treatment.#

It’s far easier to keep fleas away than it is to clean them up. If your pets are unprotected it may cost you more in the long run.

Realistically, the best treatment is one that you'll remember every single month. When searching for a solution, find one that can be easily applied and potentially shipped to your door so you remember your monthly dose.

4. Find one that works for your dog.

Above all else, the health of your dog is most important. Before using anything to kill fleas, make sure it is safe for your individual dog's needs.

The best treatment to kill fleas on dogs will depend on:

  • Your dog's breed
  • Your pet's age
  • Their weight (large dogs vs. small)
  • Any health issues
  • Pregnancy status

5. Protect every pet in your home.

Ridding all pets completely of fleas and ticks takes patience and persistence. Every time you apply flea treatment, be sure to follow the instructions for each pet’s weight class.

Wondering when to start flea and tick treatment for puppies? Every flea and tick medicine has different requirements. But generally, puppies should:

  • Be at least 7 weeks or 8 weeks old
  • Weigh at least 4 lbs
  • Not have any pre-existing health issues

And, be sure to treat every dog and cat in your household. If other pets are unprotected they may reinfect the others.

6. Treat your home in addition to your dog.#

Just because you have fleas, doesn't reflect the cleanliness of your house. But, the best way to avoid fleas from coming back is to clean up their environment.

After applying treatment, vacuum every area your dog spends time in. This can help you get rid of 30-90% of flea eggs. Discard the contents of the vacuum outside.

Next, wash all bedding and soft toys in soapy, warm water and wipe down hard surfaces. In difficult cases, a household spray with an IGR may be useful. They can help treat flea reproduction at the source.

CycleKiller - Build Your Kit

Types of flea treatments for dogs#

There's a lot of misinformation about flea and tick treatments for dogs. Now that you know what to look for, here are some options to consider:

Over-the-counter flea treatments

There are many different flea treatments available over-the-counter (OTC) for dogs. However, not all solutions are 100% effective. Most of these solutions will kill adult-stage fleas in 24-48 hours. But, there are some caveats for each type.

Topical flea treatment

Topical flea treatments have been around for nearly 30 years. After shampoos, powders, and sprays lost momentum, pet parents longed for a more effective solution. Topicals are applied to your dog’s skin and fur coat to repel and kill fleas and ticks on dogs.

Topical treatments are applied directly to your dog’s skin starting at their shoulder blades. The topical solution works to spread throughout your dog's coat via hair follicles and natural oil in their skin.

The best topical flea treatment for dogs is one that both kills fleas and repels all flea life cycle stages.


Wags Advance® for Dogs will kill adult fleas in as little as two hours after application. This topical product contains ingredients that attack the flea’s nervous system which helps kill individual fleas and stop reproduction to prevent a future flea infestation.

Flea shampoo

Flea shampoo works to eliminate fleas on contact. But, it does not prevent fleas from biting your dog in the future.

Bathing your pet with shampoo may seem like it's helping you get rid of fleas. But, a mixture of bath water and shampoo usually only kills adult fleas.

Using a fine tooth flea comb and shampoo for fleas during bath time can help in the short term. But, even professional grooming won't solve your problem if you aren't treating your pet's environment.

Wearable flea treatments

Wearable flea treatments are a less messy alternative to topical solutions. Unfortunately, they aren’t as effective as other topical flea and tick treatments.

One common example is a flea and tick collar. Your dog wears the collar around their neck, so their hind legs and tail may be less protected. Be sure to consult with your veterinarian when using flea collars and closely follow the instructions provided.

Prescription flea medication

Not long after topicals were introduced, oral flea medications made their way to veterinarians and pet stores everywhere. Because they were often paired with a heartworm preventative and given orally, they usually require a prescription from your vet.

Insect development inhibitors (IDI)

One prescription oral medication is an IDI. These ingredients are released slowly into your pet’s bloodstream over a few weeks. After a female flea bites your pet, she ingests the IDI. This stops the reproduction of future fleas.

But, there are two big cons to these types of treatments:

  1. IDI’s are ineffective at killing adult fleas so you’ll need to add another treatment.
  2. Oral treatments need a flea bite to work which can lead to infection.

Remember that every product works differently. What kills fleas on contact with one dog may not work for another. Talk to your vet about what treatment they recommend for your specific dog.

Natural flea treatment

Natural remedies to get rid of dog fleas are convenient options for pet parents. This is because essential oils and salt are often found in your cupboards.

Home remedies are usually found in your home. So, they may help solve your immediate problem. But, these solutions aren’t effective at preventing fleas on dogs naturally.

Keep in mind that just because they kill or prevent fleas on dogs naturally, it doesn't mean they are safe. They could be toxic to your pet.

Some popular natural remedies to get rid of fleas include:

Apple cider vinegar

One theory about fleas is that they don't like the smell or taste of apple cider vinegar. So, many pet parents use a 50/50 concoction of apple cider vinegar and water as a flea spray on their pets to repel fleas. However, this isn't 100% effective at warding off fleas and doesn't kill fleas on dogs instantly.

Baking soda and salt

A mixture of water, baking soda, and salt is touted as an effective way to remove fleas. Pet parents apply the paste to their pet, allow it to sit for several hours, and then vacuum it off.

Like other natural solutions, this isn't a dependable way to kill fleas and won't prevent them from infecting your pet in the first place.

Coconut oil

Coconut oil is often used to improve the skin and coat. But, it can also be used to smother and repel fleas.

Applying coconut oil (outdoors) to your dog's skin will cover and suffocate the flea. But, it can be difficult to maintain and isn't very convenient when you need a quick solution.

Diatomaceous earth

Diatomaceous earth works by sprinkling the powder throughout your home and using a vacuum to clean it (and the fleas) up. But, pet parents often apply it incorrectly or use it too much. It should not be applied to pets directly. Plus, inhalation can cause lung damage.

Essential oils

Some essential oils are naturally repelling. Spraying a mixture of warm water and oil on your pet's coat is common. But, many pets are allergic to these essential oils so it could cause other problems for your pet:

  • Citronella oil
  • Eucalyptus oil
  • Peppermint oil
  • Sage tea oil
  • Tea tree oil


Garlic is a natural remedy that is fed to pets to repel bugs because of its sulfuric quality. But, garlic is hard to dose correctly and can be toxic to your dog


If you find a few home remedies you'd like to try, be sure to talk to your veterinarian first. They can determine if natural flea remedies are right for your pet.

Pet owners know finding fleas and flea bites on your dog isn't fun. But, flea prevention is essential to your pet's health and flea freedom. Soon you will once again have a flea-free environment and happy, healthy, itch-free dogs.

CycleKiller - Build Your Kit


Meet Jocelyn Stange

As a Content Marketing Manager, Jocelyn is committed to creating expert content to help pets stay healthy and keep their humans happy. She received her MA in Journalism and Mass Communications from the University of Nebraska-Lincoln. When she's not zeroed in on content strategy you can find her attempting to teach her goldendoodle Murray a new trick.