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What Kills Fleas on Dogs Instantly?

Small Jack Russell Terrier using its hind leg to scratch the back of its head sitting outdoors.

A wide range of sprays can eliminate fleas in a brief period if used correctly. For instance, Nitenpyram (also known as Capstar) is a medicine commonly used to treat flea infestations in dogs. You can also try a variety of home treatments to get rid of fleas on dogs, like apple cider vinegar and baking soda. Keep reading to know more about the natural and commercial remedies that can kill fleas on dogs instantly.

What Kills Fleas on Dogs Fast?

If you have ever dealt with a flea infestation, you are aware of the grave danger. Despite their small size, fleas are capable of causing significant harm in a relatively short period. These parasites survive by draining blood from their hosts and cause discomfort and severe itching.

It doesn’t take long for one or two fleas to evolve into a veritable explosion of flea activity. This is because fleas can lay up to 50 eggs in a single day. (That is a significant quantity of eggs!)

The question now is: how do you kill fleas? And is there a quick way to kill fleas on dogs? Yes, you can eliminate fleas in a short amount of time, yes. Some of the ways that allow you do that are discussed below.

Natural Remedies to Kill Fleas on Dogs Instantly

Over head view of wooden bowls full of herbs, spices, and dried flowers surrounding a mortar and pestle.

Fleas are a reality and it becomes unavoidable to keep your pet safe from these pests in certain situations. Therefore, you are not a poor pet parent if your dog has fleas. However, it is helpful to know what immediately kills fleas on dogs so that you can treat your dog. Some treatments take little time and effort, while other solutions can take a while to kill fleas.

It is also crucial to use an effective flea preventative after using a medication that eliminates fleas on dogs. This ongoing treatment will ensure that the fleas don’t come back again. A huge variety of items are available in the market nowadays and making a decision could be an overwhelming task. However, if you are armed with the correct information, making a decision can be simple.

There are many options to cure your dogs if you suspect that fleas are responsible for the itching. Some of the most common among them are as follow.

Baking Soda and Salt

Box of Arm & Hammer Baking Soda isolated against a white background.

Baking soda and salt both kill fleas and their eggs by dehydrating them. Spread the mixture all over your home in a thick coating. Then, use a brush to work it into the carpet fibers and in the gaps beneath the furniture. After letting it sit for a day or two, thoroughly vacuum it.

After you are finished, give your vacuum a thorough cleaning (salt can cause rust). You should also consider the options of removing the bag or emptying the canister outdoors.

How do flea collars work? Check out our post “Do flea collars kill fleas already on dogs?” to learn more.


Microscopic view of a Nematode on a grey background.

Nematodes are found in the soil and comprise tiny worms that feed on the larvae of other insects. Certain species of nematodes can be highly beneficial in the fight against termites, grubs, and fleas. Mix the nematodes with some water and spray them all over your yard. It is essential to use the exact amount of water. Therefore, make sure you have read the instructions on the container very carefully before using this product.


Bundle of rosemary on a wooden surface

Steep the rosemary needles in water brought to a boil, then drain and dilute the mixture. When the water has cooled to a point where it is neither too hot nor too cold, pour it over your dog. Don’t forget to knead the rosemary solution into their fur.

You may also prepare a fine powder from dried rosemary, fennel, wormwood, and rue by using a pestle and mortar. The powder can then be sprinkled throughout your home. Before using it as a dip or an ingredient in the sprinkling powder, you should first ensure that your dog is not bothered by the fragrance.

Tea tree oil has been known to repel bugs, but what about fleas? Check out our post “Does tea tree oil kill fleas on dogs?” to learn more.

Apple Cider Vinegar

Store display of Bragg brand Apple Cider Vinegar

Another technique to naturally get rid of fleas on dogs is to try a combination of water and apple cider vinegar. Most people prefer apple cider vinegar for this purpose (ACV) and use equal parts of vinegar and water. However, a spray of 1:1 could be too intense for your pet. Hence, it’s better to start with a 1:3 ratio and see how your pooch reacts to it.

Brewer’s Yeast

Broken cake pieces of Brewer's Yeast isolated on a white background.

Beginning from the inside out is one of the natural approaches to treat fleas on dogs. However, it’s perhaps the least evident one. Healthy dogs are less likely to host fleas, and adding a small amount of brewer’s yeast to your dog’s food can be helpful. It will bring dual benefits because it improves your dog’s health and reduces the likelihood of a flea infestation.

An effective treatment for fleas can be made with as little as a half teaspoon of brewer’s yeast. Simply add it to your dog’s daily diet and that will be it.

Vinegar Drink

Close up of a beagle drinking water from a metal bowl.

Vinegar or apple cider vinegar, diluted in your dog’s drinking water, can also be useful for fighting fleas. However, you will need to give them a taste test to see whether they appreciate it or not. After all, you don’t want to discourage them from drinking their water if the flavor is unpleasant.

A recommended ratio is one teaspoon of the vinegar of your choice to every four cups of water. This will not only keep the fleas but the coat and skin of your dog will also profit.

Commercial Remedies to Kill Fleas on Dogs Instantly

bright green flea collar isolated on a white background.

You should always seek the suggestions of a veterinarian before commencing any flea control regimen. They are qualified to assist you in keeping your pet safe and healthy and help you establish a flea treatment regimen. Treatment strategies typically include an initial treatment to eliminate existing fleas, followed by a routine to keep fleas from troubling your dog. The following are some of the best commercial products to kill fleas on dogs instantly.


Nitenpyram, better known by its brand name Capstar, is the medication used the most frequently to rid dogs of fleas immediately. This pill can be taken orally once and effectively against fleas within half an hour of administration. When using Capstar, it is strongly advised that you keep your pet confined to limited space. A sheet or blanket on which your pet may rest can help capture fleas as they fall off, making flea removal much more straightforward. Capstar is a highly successful medication that may be obtained from your local veterinarian or purchased over-the-counter from various internet pet supply retailers.

Flea Shampoo

Person squirting soap onto the head of a Jack Russell Terrier standing in a bathtub.

Specialized flea shampoos, which clean the skin and eliminate fleas immediately, may be highly recommended by your veterinarian. After giving the pet a thorough bath, the next step is to use flea combs that have been specifically developed to remove any eggs that may still be present.

Lufenuron, an insect growth inhibitor, is another product that may be obtained through your veterinarian. It must be taken once a month in pill form and does not kill adult fleas, but it does stop their offspring from reproducing.

Neem Oil Spray

Neem oil in a brown glass bottle.

A natural insect repellant, Neem oil is a lesser-known yet potent flea treatment. To keep fleas away from your dog’s coat, you may use this oil, which is native to Burma, Sri Lanka, and portions of India. It may also be used as a flea spray if you dilute it.

Aromatherapy Spray

Brown glass spray bottle, laying next to a lemon and mint leaves isolated on a white background.

If you are familiar with aromatherapy, you may prepare a batch of aromatherapy that will treat a flea infestation and prevent future infestations, and function as a natural soother for your dog. This is possible if you manufacture the aromatherapy yourself. Try using sweet almond oil as the foundation oil, and then add drops of Atlas cedar oil, lemon eucalyptus oil, geranium oil, bay laurel oil, standard myrrh oil, and lavender oil.

Coconut Oil

Coconut oil in a clear glass bottle stoppered with a cork, sitting on a wooden table next to a half of a coconut.

Is there anything that can’t be accomplished using coconut oil? When it comes to treating fleas, coconut oil can be helpful in various ways. Not only will rubbing a teaspoon of coconut oil straight into your dog’s coat keep fleas away, but it will also make the hair lustrous and diminish its overall body odor. Because of its antibacterial, antifungal, and antiviral qualities, coconut oil can even help treat intestinal parasites in dogs if it is given to them in addition to their regular diet.

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Please note: We are not veterinarians and you use our advice at your own discretion. We always recommend that you consult your veterinarian whenever you have health-related conditions your furbaby is facing. With that in mind, as pet parents ourselves, we wish nothing but the best for your pet and their healthy and happy lives.