What is the best flea prevention for dogs?

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What is the best flea prevention for dogs? - a dog receiving a topical flea treatment

Fleas are the most common external parasite in dogs and can cause discomfort, irritation, and even diseases in dogs and their human companions. Flea prevention is an important part of dog ownership that keeps your pet happy and healthy. Read on if you have ever wondered:

  • What kinds of flea preventatives are available for dogs?
  • Can dogs have a negative reaction to flea prevention?
  • Why is it important to prevent fleas?
  • What are the signs and symptoms of fleas?
  • What type of flea prevention should I choose?

Fleas are not only an annoyance but also capable of carrying diseases and causing other conditions in dogs and people. Flea prevention is the best way to keep these tiny pests off of your furry friend and out of your home.

How can I prevent flea infestations on my dog?

There are many products available that keep fleas at bay. Many of these flea prevention products also protect against ticks, heartworms, and other external and internal parasites. Fleas infest an environment and not just one pet, so every pet in the household needs flea preventative to avoid flea infestations. Products that offer protection against fleas are available over-the-counter and as prescription products. Talk to a vet to learn which products are safe and effective for your pets. Products such as flea shampoos, powders, and pet sprays do little to treat fleas, so vets typically recommend topical applications, oral flea medicine, and flea collars. Always make sure to tell your vet if there are other animals in the household when discussing external parasite control. Many products that are safe for dogs are toxic to cats, even indirectly.

Topical treatments

Topical treatments, or spot-on treatment products, come in single doses that are applied to the skin between the shoulder blades. They kill fleas and prevent them from breeding in the fur. Topical medications typically require monthly application. There are many topical treatments available containing a variety of active ingredients. However, not all topical products are the same and some are safer and more effective than others.


  • Readily available over-the-counter and as a prescription
  • Some topical options are cheaper than oral medications
  • Often effective against multiple parasites


  • Some canine topical flea treatments are unsafe to use in a home that is shared with cats, even if the medication is not applied to a cat directly
  • Swimming and bathing may decrease the effectiveness
  • Some formulations leave a greasy spot on the fur for a few days after application
  • Some dog owners find the smell of the medication unpleasant
  • May cause skin irritation in some dogs

Oral medications

Oral treatments are given as a treat, tablet, or pill, usually every one to three months. They rapidly kill fleas that bite and prevent them from breeding. Oral flea preventives are usually only available as a prescription. There is also an over-the-counter rapid knockdown pill that rapidly eliminates adult fleas but does not have enough potency to prevent recurrence if exposure is ongoing.


  • Often effective against multiple species of external and internal parasites
  • No risk of exposing cats in close contact to dangerous chemicals
  • No greasy spots or strong odors
  • Manageable dosing schedule (one to three months)


  • Requires a prescription
  • More expensive than other options
  • Are not effective if spit out or thrown up
  • Can cause stomach upset in some patients

Flea collars

Flea collars repel fleas with insecticides and have the advantage of lasting multiple months. They are made with a variety of ingredients and choosing a flea collar that is safe and effective can be challenging. If you would like to use a collar preventative for your dog, talk to a veterinarian to find the right collar.


  • Some last multiple months
  • May be more cost-effective than other options
  • Some also repel and prevent ticks


  • Difficult to find a safe and effective option
  • Not safe to be chewed on or ingested
  • Must be tight and have skin contact
  • Some are not safe to use around cats
  • May cause skin irritation for some dogs with sensitive skin

Yard treatments

Treating your lawn with pesticides, maintaining your yard, and keeping out wildlife can help limit your dog’s exposure to fleas. However, yard management is not a replacement for flea prevention medication. Many of the most effective forms of flea control products for pets also provide some degree of environmental treatment as the medication continues working to kill flea larvae in furniture and carpets as your dog sheds dander. If you want to treat the yard for fleas, work with a professional to ensure the product is safe for your pets.

Do natural flea preventatives work?

There are no natural or homeopathic flea preventatives that work. Natural deterrents, such as fencing out wildlife, can help limit exposure but do not provide complete protection. Flea prevention that has not been approved by a vet, such as essential oils and amber resin collars, do not provide complete protection and many are unsafe.

Can my dog have an adverse reaction to flea prevention?

Side effects of flea prevention can happen but are more likely to occur with over the counter products used outside of veterinary guidance or due to improper use of prescribed products. Always give size- and species-appropriate doses. Avoid giving your dog medication meant for a cat or for a dog of a different size in order to prevent toxicosis. Never split a dose between two animals. Finally, always use veterinarian-recommended products.

Even when used properly, flea preventives can cause adverse reactions. Flea collars and topical solutions may cause skin irritation where the product touches the skin, especially for dogs with sensitive skin. Oral preventatives can sometimes cause stomach upset. In rare cases, some dogs with a history of seizures or neurologic disorders may have neurological side effects from oral flea preventatives. If your dog has an underlying medical condition, discuss the best option with a veterinarian.

Why is flea prevention for dogs important?

Fleas are one of the most common triggers for allergies in dogs, resulting in many pets suffering from flea allergy dermatitis (FAD) if they are not consistently on preventive medication. Beyond preventing FAD, flea preventative is important to avoid the spread of flea-transmitted diseases, such as bartonellosis, to dogs as well as people. Ingesting infected fleas is one way dogs can pick up tapeworms. Young puppies and very tiny dogs can also develop life-threatening anemia from flea infestations due to blood loss as the fleas feed.

How do I know if my dog has fleas?

Fleas are the most common external parasite in dogs and cats. Adult fleas can be difficult to see, and flea eggs and larvae are nearly impossible to see with the naked eye. Dogs typically catch fleas outdoors during the warmer months but can become infested year-round. A dog often shows few to no symptoms of fleas unless they are allergic to flea saliva or another condition arises. Your dog may have fleas if:

“Many flea infestations in dogs go unnoticed until a pet in the household develops flea allergy dermatitis,” explains Dr. Jo Myers, a Vetster veterinarian. “Even if the other pets in the home appear fine, rest assured they are also infested with fleas and need treatment.” Flea eggs fall from one host, hatch in the environment, and hop on to a new host once they are fully grown fleas, affecting all animals in the home.

How do veterinarians diagnose and treat fleas on dogs?

Fleas are diagnosed by the presence of adult fleas, flea dirt, or dermatitis symptoms, such as itchy skin. Finding no fleas on a dog does not rule out the possibility of infestation. Fleas are treated with flea control products for a minimum of three months to ensure all fleas have been exterminated. If other symptoms or conditions are present, they will be treated alongside treatment for fleas. After successfully treating a dog for fleas, year-round flea preventative is usually necessary to protect against future infestation.

What is the best kind of flea prevention?

There is no one-size-fits-all flea preventative for dogs. The best way to ensure you are purchasing a safe and effective product is to talk to a veterinarian. As long as the product is vet-approved, the type of preventative depends on the pet parent’s preference, the dog’s tolerance and lifestyle, the level of exposure, and the owner’s finances. Be careful with over-the-counter medications, as some are not effective or safe. If you would like to discuss the best flea-preventative options for your dog, you can chat with an online vet to get recommendations and a prescription.

FAQ - What is the best flea prevention for dogs?

How long does it take to get rid of fleas on a dog?

Dogs must be on flea prevention for a minimum of three months to effectively kill the entire flea life cycle. Every other pet in the home must also be on flea prevention to eradicate the infestation. Treating the furniture, carpets, and bedding can also help.

What is a natural flea preventative?

There is no effective natural flea preventative, and some of the homeopathic or natural options are unsafe or even toxic for dogs. Always use a vet-recommended flea product for prevention.

Do indoor dogs need flea prevention?

Indoor dogs can still get fleas from other pets that go outside, and an infested neighbor in your apartment building can transmit fleas to your dog as well. Even if your dog never sets foot outside, they could still be exposed to fleas through screens, open doors and windows, or people carrying fleas indoors unknowingly. Talk to your veterinarian about your dog’s risk for fleas and what the best flea prevention option is for their lifestyle.

What time of year do dogs get fleas?

Dogs are most commonly infested with fleas in the warmer months of the year. However, fleas can breed in carpets and furniture and survive indoors during the cold winter months, causing winter infestations. Year-round prevention is the best way to fully protect your dog from fleas.