Safe Mosquito and Fly Repellent for Dogs

owner applying topical flea and tick ointment to a dog

Tatomm / Getty Images

Although your canine companion is outfitted in a thick, fluffy coat, that layer of fur provides little protection against biting insects, such as mosquitoes and flies. While the bites of these insects can be irritating, leaving itchy welts behind, they can be more dangerous, transmitting heartworm disease, West Nile virus, or tularemia. A variety of veterinarian-approved, prescription products are available to battle biting insects, as well as a many over-the-counter products. But what about human products or natural alternatives? Let’s discover what products work well to protect your dog from biting insects, and what should be avoided. 

What mosquito and fly repellents should be avoided in dogs?

Popular repellents for people who spend time outdoors contain DEET, a highly effective chemical that repels biting pests, such as mosquitoes, flies, and ticks. While this ingredient works well for people, it can be toxic for pets, especially in high concentrations. If you use a product containing DEET on your dog, you may notice the following signs:

  • Ocular exposure can lead to conjunctivitis, blepharospasm, squinting, tearing, lethargy, scleritis, and corneal ulcers.
  • Inhalation exposure can cause airway inflammation and difficulty breathing.
  • Gastrointestinal issues, such as vomiting, diarrhea, and inappetence, are common with any form of DEET exposure.
  • With exposure to a high-concentration DEET product, you may notice ataxia, disorientation, tremors, and seizures.

Many pets attempt to groom strange substances off their skin and fur, which commonly leads to a DEET toxicity, but poisoning can still occur through inhalation or accidentally spraying a product in the eyes. 


DEET and other human insect repellents should not be applied to dogs or cats. This chemical is toxic when ingested at high doses, and dogs may lick it off and ingest it, potentially resulting in toxicity.

If your dog displays any signs of toxicity after DEET exposure, contact your veterinarian or emergency veterinarian immediately. 

What mosquito and fly repellents are safe for dogs?

Two main chemicals are highly effective at battling biting insects: picaridin and permethrin. These chemicals are found in many canine flea, tick, and mosquito preventives, as they repel biting insects before they can make a meal out of your pet. 

  • Picaridin is derived from an organic compound that gives black pepper its hot flavor. Unlike DEET, picaridin is not a neurotoxin, but instead works by disrupting the insect’s sense of smell, and has been shown to be effective against ticks, mosquitoes, sand flies, gnats, midges, chiggers, and biting flies.
  • Permethrin is a synthetic chemical that acts similar to natural extracts from the chrysanthemum flower. This chemical works by targeting the nervous system of pesky parasites, paralyzing them and preventing them from biting or moving. Permethrin works more as an insecticide, killing biting insects, but it can also repel ticks before they bite and attach.

 Two safe topical mosquito and fly repellents for dogs include:

  • K9 Advantix II—This monthly topical product contains several insecticides, including permethrin, making it highly effective at repelling and killing biting insects. K9 Advantix II kills fleas, ticks, mosquitoes, and chewing lice, and also repels biting flies. Because this product kills insects through contact, pests don’t have to bite your dog to die.


This product is also toxic to aquatic life. Dogs should not be allowed to swim for 48 hours post-application of K9 Advantix II.

  • Vectra 3D—This product is also a monthly topical containing several insecticides, with a focus on permethrin. Vectra 3D’s ingredient combination causes a “hot foot” reaction in flies, ticks, fleas, mosquitoes, mites, and lice, forcing the insect to retreat up the hair shaft without biting your dog. Mosquitoes sense the active ingredients in Vectra 3D, and 80% of the time, avoid dogs without landing.

Your veterinarian can help guide you towards picking an appropriate product to protect your dog from biting insects.

What natural methods can keep my dog safe from biting insects?

To complement the preventive product you use for your dog, try these chemical-free methods to help avoid biting insects from making a meal out of your pup:

    • Turn your yard into a bug-free oasis by choosing your plant life carefully. While some flowers, bushes, and shrubs are designed to attract certain insect species, others will help form a shield around your home. Persuade biting insects to inhabit a different yard by planting the following flora:
    • Lemon balm
    • Catnip
    • Basil
    • Lavender
    • Peppermint
    • Citrosum
    • Lemongrass
    • Marigold
    • Rosemary
  • When heading outdoors with your pooch, choose a time of day when insects are the least active. Mosquitoes prefer early morning and late evening, around dawn and dusk, while flies enjoy the entire day before settling in for the night.
  • Remove prime breeding areas for mosquitoes by preventing stagnant water buildup in pots, tarps, or other items that can trap water.
  • Prevent access to a tasty food source for flies by keeping the lid shut tightly on your trash can. Pick up all waste and refuse that may blow into your yard, as flies are attracted to rotting food.
illustration of safe and toxic insect repellents for dogs and cats
The Spruce / Ashley Nicole DeLeon

What natural mosquito and fly repellents are unsafe for my dog?

Many pet owners prefer to use natural products for protection against mosquitos, flies, and other biting insects for their dogs, rather than potentially harsh chemicals. In reality, most natural methods are mildly effective at best, but they can also be toxic to dogs. Essential oils and other DEET-free alternatives can lead to toxicity in your dog, so avoid products that lack research studies on the safety in pets. When in doubt about the safety of a natural product for your dog, contact your veterinarian before administering, especially if your pet is very young or very old. 

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.
Article Sources
The Spruce Pets uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Don’t DEET That Dog. ASPCA Animal Poison Control Center

  3. Pet-friendly mosquito repellents (that humans can use too). Animal Humane Society

  4. Lee, Mi Young. Essential Oils as Repellents against ArthropodsBioMed research international vol. 2018 6860271. 2 Oct. 2018, doi:10.1155/2018/6860271