Safe Mosquito and Fly Repellent for Dogs and Cats

Itchy dog biting its leg outside

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Furry hair coats help somewhat, but dogs and cats get bitten by mosquitoes, flies and other insects just like we do. Biting insects are not only bothersome; they may transmit deadly diseases such as heartworm and West Nile Virus.

Knowing What Not to Apply

DEET is the most effective mosquito repellents for humans. It should be applied to clothing and exposed skin. 


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 and cats may lick it off and ingest it, potentially resulting in toxicity.

With DEET ingestion, clinical signs may include:

  • Drooling
  • Wobbly gait
  • Seizures
  • Vomiting
  • Loss of appetite

If your pet has ingested DEET, please contact your veterinarian or emergency veterinary clinic for advice.

illustration of safe and toxic insect repellents for dogs and cats
The Spruce / Ashley Nicole DeLeon

Safe Insect Repellents for Dogs

One spot-on topical product, K9 Advantix II® by Bayer Animal Health, repels mosquitoes in addition to fleas, ticks, and flies for up to 30 days.

The Bayer Pet Parents website says that K9 Advantix II provides broad-spectrum protection against fleas, ticks, and mosquitoes, too. It not only kills but also repels. Fleas, ticks, and mosquitoes don't have to bite or attach to die.

That is great news for dogs in need of effective parasite and insect repellent. It is important to note that this product contains permethrin, which is very toxic to cats.

The K9 Advantix Spot-on is only for dogs, and for households containing both dogs and cats, pets must be kept separated until the product application areas on the dog is completely dry. Cats must be prevented from grooming those areas on their canine friends. If your cat ingests this product, please seek veterinary attention immediately.


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

There are many "natural" and insecticide-based sprays available on the market for dogs, available online or at pet supply retailers. It is best to a) identify what insect(s) you are wanting to repel, and b) check with your veterinarian if the product is appropriate and safe for your pet. Extra caution for the very young, very old and pets in poor health or on other medications.

Safe Insect Repellents for Cats

Cats are another story. They metabolize drugs and chemicals very differently from humans and dogs, and "safe" compounds for us may be quite toxic to cats. Plus, they are good groomers, which leads to possible ingestion as well as absorption through the skin.

While there are some "natural" products available for cats, it is always best to check with your veterinarian first. Many natural preparations contain essential oils, and some of these oils are toxic to cats.

What About Avon Skin-So-Soft?

This product is often brought up as a safe non-DEET alternative for people and pets. Research studying Skin-So-Soft versus other repellants suggests that, if anything, SSS traps the insects in the oily film instead of repelling them.

The duration and effectiveness of this product are often debated. There are no known instances of toxicity for humans or pets but use caution with cats, who often groom and ingest products that may be harmful.

Essential Oils, Garlic, and Other Natural Repellents

Caution is advised, for both dogs and cats. Many of these ingredients are ineffective insect repellents and some are toxic.


Garlic is toxic to pets. As noted above, essential oils are common ingredients for "non-chemical" applications, and many of them are toxic to cats.

While not 100 percent effective, keeping cats indoors will greatly reduce the numbers of insect bites and stings.

Screen Away Insects

Since ears and faces are the most accessible area of dogs and cats for insects, a face bonnet screen may help. At least for dogs.

Nancy Kay, DVM DACVIM (author of Speaking for Spot) reviewed the OutFox Field Guard™—a product designed to prevent foxtails from entering ears, eyes, and mouths of dogs.

Foolproof Insect Avoidance

Avoiding outdoor activities during times of day when insects are most active helps lower exposure. Mosquitoes are most active early in the morning and evening. Flies are active throughout the day, but face screens or keeping your pet indoors will help.


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.