The short answer
- Keep your dog away while it is applied and until the treated area is dry.[1][3]
- Exposed pets may vomit or have diarrhea once, be less active, twitch their ears, flick their paws, or drool.[2]
- If your dog contacted wet spray or the concentrate, call your veterinarian or ASPCA Animal Poison Control.[4]
- The pet signs NPIC lists for pyrethroids like bifenthrin are typically minor and pass on their own. Veterinary case reports also describe severe poisonings: a dog that ate powdered bifenthrin had tremors that were hard to control, and another dog found having a seizure at home died.[6][8][9]
If someone may be poisoned
What bifenthrin is and where dogs meet it
Bifenthrin is a pyrethroid insecticide, a human-made relative of the pyrethrins that come from chrysanthemum flowers. It is sold in sprays, granules and aerosols, in more than 600 products in the United States, and is used on farm crops and in homes.[2]
It acts on the nervous system of insects that eat or touch it. NPIC explains that it is more toxic to insects than to people because insects have lower body temperatures and smaller bodies.[2]
Bifenthrin products for homes and yards are not pet treatments. FDA's Center for Veterinary Medicine says that if a product is for use in the house or yard, don't put it directly on your pet. For flea and tick products made to go on a dog, see the flea and tick section of the guide to pest control with pets.[7]
What the label says
The label's signal word is CAUTION. Under 'Hazards to Humans and Domestic Animals' it says the product is harmful if swallowed, inhaled or absorbed through skin.[1]
- 'Do not apply to pets, crops, or sources of electricity.'[1]
- 'Do not allow contact with treated surfaces by people or pets before spray has dried.'[1]
- For indoor flea treatment in areas pets use, the dilution must not be applied directly to pets, and the treatment must be dry before pets come back.[1]
- Around ornamental ponds, applicators are told to take care to avoid fish and reptile pets.[1]
- For termite treatments next to a house, people inside are to take their pets and themselves out if they see the product leaking, and people and pets must stay out of any contaminated area until it has been cleaned up.[1]
How dogs get exposed
The label and NPIC both focus on the same exposure: pets touching treated surfaces before the spray has dried.[1][3]
Bifenthrin does not absorb well through skin, according to the studies NPIC reviewed.[2]
The label and NPIC put skin contact a little differently. The label warns the product is harmful if absorbed through skin. NPIC's technical fact sheet rates bifenthrin low in toxicity on the skin of rats and rabbits, with an acute dermal LD50 above 2000 mg/kg.[1][6]
Swallowing is the bigger concern. In a 13-week study cited by NPIC, dogs fed technical-grade bifenthrin every day developed tremors at doses of 5.0 mg/kg and above; 2.5 mg/kg was the no-observed-adverse-effect level. Bifenthrin eaten by an animal is absorbed slowly, and most of it leaves the body within 3 to 7 days. NPIC stopped writing technical fact sheets in 2011 and says the archived ones may be out of date.[6][2]
Once a spray dries on the ground, bifenthrin binds tightly to soil and is unlikely to become airborne from soil surfaces. It also lasts: NPIC gives a half-life in soil of 97 to 250 days, depending on soil type.[2][6]
Bifenthrin is highly toxic to fish and very highly toxic to bees. Cover fish tanks before any indoor treatment.[2][3]
Signs of bifenthrin exposure in dogs
NPIC lists single-episode vomiting or diarrhea, reduced activity, twitching of the ear, paw flicking and drooling. Its technical fact sheet says these signs are typically self-limiting and considered minor.[2][6]
Other signs veterinarians have seen in cats and dogs exposed to pyrethroids start with hyperexcitability, followed by incoordination, diarrhea, depression and dilated pupils. Some cases also had chewing, head bobbing, partial paralysis and whole-body tremors.[2][6]
Two veterinary case reports show how bad it can get when a dog gets into the product itself. In a 2024 report from North Carolina State and Kansas State veterinary authors, an 8-month-old dog ate an unknown amount of powdered bifenthrin and developed altered mentation and tremors that did not respond to IV fluids, lipid emulsion, anticonvulsants or methocarbamol. It recovered after plasma exchange, a treatment during which its heart stopped and it had to be resuscitated.[8]
In a 2019 report from Michigan State University's veterinary diagnostic laboratory, a 5-year-old dog left unsupervised at home for 15 to 20 minutes was found having what looked like a seizure. Despite aggressive treatment at an emergency hospital it died 28 hours later, and bifenthrin was found in its tissues. The authors describe it as the first reported dog death from bifenthrin.[9]
Using it around a dog
- Remove the dog, its toys, bowls and bedding before treating.[3]
- Wait until the treatment has dried and the area is ventilated before letting the dog back.[3][1]
- If a company treats your yard, ask what they are using and what it means for your pets.[3]
- Granular lawn products may mean keeping the dog off the treated area for 24 hours or longer while the granules dissolve and the area dries. The label may give more specific instructions.[3]
- Don't spray near pet food or water dishes.[5]
Storing it where a dog can't get it
The dog in the 2024 case report ate the product itself, so storage matters as much as re-entry time. EPA advises keeping pesticides in their original containers, since containers without tight lids spill easily and a pet can get into them, and putting a pesticide in a food or drink container is very dangerous.[5][8]
If your dog got into bifenthrin
Call your veterinarian or the animal poison control line above. Have the product label with you when you call, because it tells the people helping you what the product is. That's one more reason to keep the original container. To report the incident afterward, see 'After a reaction: who to tell' in the guide to pest control with pets.[5][4]
Common questions
- How long after spraying bifenthrin can my dog go outside?
- Until the spray has dried, per the label, and NPIC adds that the area should be well ventilated. Granular lawn products may need 24 hours or longer while the granules dissolve and the area dries. Check the product label for anything more specific.[1][3]
- Can I spray bifenthrin on my dog for fleas or ticks?
- No. The label says not to apply it to pets, and FDA says a house or yard product shouldn't go directly on a pet. Ask your veterinarian about a product made and labeled for dogs.[1][7]
- Is a dog that walked on a dry treated lawn in danger?
- The label and NPIC use dry as the point when pets may return. NPIC reports that bifenthrin does not absorb well through skin and that the pet signs reported are usually minor and self-limiting. Watch for the signs listed above and call your vet if you see them.[1][3][2][6]
- What about cats?
- NPIC's list of signs comes from veterinary observations of both cats and dogs exposed to pyrethroids. FDA warns that a flea or tick product made for dogs shouldn't be used on cats. For permethrin, another pyrethroid, see the guide on whether permethrin is safe for cats.[6][7]
Sources
- U.S. EPA Pesticide Product Label System, “Bifenthrin TC (Bifen I/T) label, EPA Reg. No. 53883-118 (EPA-stamped, September 1, 2026).” www3.epa.gov/pesticides/chem_search/ppls/053883-00118-20260901.pdf (accessed 2026-11-10)
- National Pesticide Information Center, “Bifenthrin General Fact Sheet.” npic.orst.edu/factsheets/bifgen.html (accessed 2026-11-10)
- National Pesticide Information Center, “Pesticide Use Around Pets.” npic.orst.edu/health/pets.html (accessed 2026-11-10)
- ASPCA, “ASPCA Animal Poison Control Center.” www.aspca.org/pet-care/animal-poison-control (accessed 2026-11-10)
- U.S. Environmental Protection Agency, “Read the Label First: Protect Your Pets.” www.epa.gov/pets/read-label-first-protect-your-pets (accessed 2026-11-10)
- National Pesticide Information Center, “Bifenthrin Technical Fact Sheet (archived).” npic.orst.edu/factsheets/archive/biftech.html (accessed 2026-11-10)
- U.S. Food and Drug Administration, Center for Veterinary Medicine, “Safe Use of Flea and Tick Products in Pets.” www.fda.gov/consumers/consumer-updates/safe-use-flea-and-tick-products-pets (accessed 2026-11-10)
- Journal of Veterinary Emergency and Critical Care, abstract via PubMed, “Fitzgerald AH et al. 2024. Successful treatment of bifenthrin toxicosis using therapeutic plasma exchange.” pubmed.ncbi.nlm.nih.gov/38708999/ (accessed 2026-11-10)
- Journal of Analytical Toxicology, abstract via PubMed, “Buchweitz JP, Mader D, Lehner AF. 2019. Bifenthrin Fatality in a Canine: A Case Report with Postmortem Concentrations.” pubmed.ncbi.nlm.nih.gov/30007355/ (accessed 2026-11-10)