What Kills Fleas Instantly on Dogs: Types of Flea Treatments

What Kills Fleas Instantly on Dogs: Types of Flea Treatments

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

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.

Fleas are a common problem among pet owners but are easily managed with the right approach. Find out what kills fleas and the treatments available to your pet.

What is the best way to get rid of fleas on a 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 pet’s needs.

The treatment you choose will depend on your pet’s:

There are a lot of options when it comes to flea and tick prevention. From powders and dips to flea collars and prescription drugs, it’s important to find the right solution for your pet.

Let's dive into each option so you can make the best decision to treat fleas.

Types of flea treatments for dogs

Here are a few options if you're currently battling fleas or want to prevent them in the future.

Over-the-counter flea treatments

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

Fast-acting tablets

If you need help combating fleas quickly, an oral fast-acting tablet might be your go-to. These treatments contain the active ingredient Nitenpyram which can kill adult fleas in under 12 hours. These products are best used to treat an active infestation with a complementary preventative product to kill flea eggs and larvae.

Oral flea treatment

One common OTC oral medication is an insect development inhibitor (IDI). These pills release slowly into your pet’s bloodstream over a few weeks. After the female flea bites your pet she will ingest the IDI which will stop 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.

Topical flea treatment

Topical treatments are applied directly to your dog’s skin and coat. The topical solution spreads throughout your pet’s haircoat by the oil on their skin and attaches to their hair follicles. The best topical flea treatment for dogs is one that both kills and repels all flea life cycle stages.

Some examples include:

Wearable flea treatments

Wearable flea treatments, like flea and tick collars, are a less messy alternative to topical solutions. Unfortunately, they aren’t as effective as other topical flea and tick treatments. Because your pet wears the collar around their neck, your dog’s hind legs and tail may be less protected.


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

Prescription flea medication

If you are looking for a combination treatment your veterinarian may be able to write a prescription. Prescription flea medications can come in pill form or topical solutions. Because each brand works differently, what kills fleas on dogs with one may not work for another. Talk to your veterinarian about what treatment they recommend for your specific dog.

Natural flea treatment

Home remedies and natural flea treatments are convenient options for pet parents because they can find many items in their cupboards. While they seem to solve your problem right away, these solutions aren’t effective at preventing future infestations.

In fact, some may be toxic to your pets. Some examples of natural remedies you should avoid include:

What’s the most effective flea treatment for dogs

No matter what you choose, the best way to get rid of fleas is through continuous prevention. Here’s what you should know to effectively prevent fleas.

1. Look for key active ingredients.

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

The most effective flea treatment for dogs includes active ingredients that kill and repel fleas and ticks.

Active ingredients in common flea and tick medications

Kills fleas
Kills ticks
Kills mosquitoes
Kills flea eggs & larvae
Repels pests
Safe for cats
Fipronil Yes! Yes! Yes!
Permethrin Yes! Yes! Yes! Yes! No
Imidacloprid Yes! Yes!
Nitenpyram Yes! Yes!
Methoprene Yes! Yes!
Pyriproxyfen Yes! Yes!

2. Be consistent about your treatment.

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

Leaving pets unprotected can really add up. That’s why year-round prevention is your best strategy for avoiding fleas.

3. Apply properly every time.

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

4. Take care of your home.

After applying treatment, vacuum every area your pets spend time in. This can help you get rid of 30-90% of flea eggs. Discard the contents of the vacuum outside or place the debris in water to kill any fleas or flea dirt collected.

Next, wash all bedding and soft toys in hot water and wipe down hard surfaces. In difficult cases, an insect growth regulator (IGR) may be helpful. This helps break up flea breeding grounds to prevent future reproduction.

5. Stay the course.

Soon you will once again have a flea-free environment and happy, itch-free dogs. Pet owners know treating fleas is no fun. But, stay the course and you’ll be well on your way to flea freedom.

Need help fighting fleas & ticks? We can help!