DEET is toxic to dogs. Both skin contact and ingestion can cause neurological symptoms ranging from tremors to seizures, and the ASPCA classifies it as a hazard for both dogs and cats. The risk scales with concentration: products containing 80% or more DEET pose the greatest danger, but even lower-concentration formulas can cause problems with large enough exposure.
Why DEET Is Dangerous for Dogs
DEET (the active ingredient in most human insect repellents) affects the canine nervous system. In a one-year study where dogs received DEET orally at various doses, animals given the highest dose (400 mg/kg/day) developed ataxia (loss of coordination), tremors, abnormal head movements, and convulsions. They also showed increased vomiting and excessive drooling. The study determined that 100 mg/kg/day was the highest dose that produced no observable adverse effects, meaning toxicity has a clear threshold, but that threshold is easy to cross when a dog ingests concentrated repellent.
The most common sign of DEET exposure is gastrointestinal upset: vomiting, drooling, and loss of appetite. With higher concentrations or larger amounts, the symptoms shift to neurological territory. Disorientation, muscle tremors, wobbling, and seizures can all occur. In rare cases, DEET exposure can be fatal.
How Dogs Typically Get Exposed
Direct application is the most obvious risk. Some owners, trying to protect their dog from mosquitoes or ticks, spray a human repellent on the dog’s coat. This is never safe. Dogs groom themselves by licking, which turns a skin exposure into an oral one.
The more common and sneaky route is secondary contact. You spray DEET on your arms and legs, your dog nuzzles against you or licks your skin, and suddenly they’ve ingested the chemical. This is especially likely with affectionate dogs that lean into you or lick your hands and ankles. The higher the DEET concentration in your product, the more risk each lick carries.
What Concentration Matters
Not all DEET products are equally dangerous. A spray with 10% to 30% DEET poses a lower (though still real) risk than the heavy-duty 80% to 100% formulas designed for deep woods or tropical travel. High-concentration products are the ones most likely to trigger serious neurological symptoms like seizures and disorientation, even from a single significant exposure. Lower-concentration products more commonly cause vomiting and stomach upset, though large exposures can still produce nervous system effects in rare cases.
What to Do If Your Dog Is Exposed
If your dog licked a small amount of DEET from your skin, watch for vomiting, drooling, or changes in coordination over the next few hours. Mild stomach upset from a brief lick of a low-concentration product often resolves on its own, but call your vet or the ASPCA Animal Poison Control Center (888-426-4435) to be safe.
If your dog ingested a DEET product directly, such as chewing on a spray bottle, do not try to induce vomiting. DEET-containing liquids can be aspirated into the lungs during vomiting, which creates a second, potentially worse problem. You can offer milk to help dilute the chemical in the stomach. Get to a veterinarian as quickly as possible. For tremors or seizures, veterinary treatment typically involves anti-seizure medication and decontamination.
If DEET was applied to your dog’s skin, wash the area thoroughly with mild dish soap and warm water to remove as much as possible before the dog licks more of it off.
Safer Ways to Repel Bugs Around Dogs
The simplest approach: use your DEET repellent, then keep your skin away from your dog’s mouth until the product has fully dried and you’ve washed your hands. Wear long sleeves and pants to create a barrier between treated skin and your pet.
If you want to skip DEET entirely, a few alternatives are considered safer around dogs. Picaridin-based repellents are effective against mosquitoes and ticks and are generally regarded as less toxic to pets, though you should still avoid letting your dog ingest them. Lemon eucalyptus oil is gaining popularity as a natural mosquito repellent for humans, but check with your vet before using any essential oil product around your dog, since some essential oils are toxic to pets even when they’re plant-derived.
For protecting your dog specifically, stick to veterinary-approved flea and tick preventatives. These are formulated for canine physiology and tested at appropriate doses. They protect against the parasites dogs actually encounter and don’t carry the neurological risks that human repellents do.