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Fipronil

Fipronil and Pets

Find out if Fipronil is toxic to dogs and cats.

Dogs: Limited
Cats: Toxic

Think your pet ate something toxic?

Call ASPCA Animal Poison Control Center: (888) 426-4435 or view emergency guide

Fipronil is a phenylpyrazole insecticide widely used in flea and tick control products such as Frontline. When applied according to the label at the correct species and weight, it is generally well tolerated by dogs. However, it is not risk-free: overdoses, ingestion of spot-on fluid, or use of the wrong formulation can cause toxicity.

Cats are particularly vulnerable. Dog-specific fipronil products may contain higher concentrations or be combined with other ingredients that are dangerous to cats. Even close contact with a recently treated dog can expose a cat to enough product to cause illness, especially if the cat grooms the dog.

Overdose or accidental ingestion can lead to neurological signs, including tremors, seizures, and loss of coordination. Other signs include vomiting, diarrhea, excessive drooling, dilated pupils, and lethargy.

Prevention is key. Always choose a product labeled specifically for your pet's species and weight, apply only the recommended amount

Is Fipronil Toxic to Dogs?

Generally safe when used exactly as directed for the correct species and weight, but overdoses, ingestion, or inappropriate formulations can cause neurological and gastrointestinal toxicity.

Is Fipronil Toxic to Cats?

Dog fipronil products and overdoses can cause serious toxicity in cats; even contact with a recently treated dog may trigger illness, especially if the cat grooms the dog.

Active Ingredients

  • fipronil

Pest Targeted

  • fleas
  • ticks
  • lice

Formulation

topical spot-onsprayoral chewpremise spray

Signal Word

caution

Application Area

animal skin and environmental premises

EPA Registration Number

EPA Reg. No. varies by product

Symptoms to Watch For

  • tremors
  • seizures
  • ataxia
  • hypersalivation
  • vomiting
  • diarrhea
  • lethargy
  • dilated pupils
  • skin irritation
  • anorexia

What If My Pet Was Exposed to Fipronil?

Contact your veterinarian or a pet poison control center immediately. Do not induce vomiting. If the wrong product was applied or an overdose occurred, wash the area with mild dish soap and rinse thoroughly; keep cats separated from recently treated dogs until the product is fully dry.

Sources

Vet's Note

PetPilot provides general information for educational purposes. While we reference authoritative veterinary organizations, this page has not been individually reviewed by a veterinarian for your specific pet. Individual animals may react differently based on age, weight, breed, health conditions, and amount consumed. Always consult your veterinarian or a poison control center for personalized advice, especially if your pet is ill, injured, pregnant, nursing, or on medication.

Medical DisclaimerThe content on this page is not a substitute for professional veterinary diagnosis, treatment, or emergency care. If you suspect your pet has been exposed to something harmful, contact your veterinarian or call ASPCA Poison Control or Pet Poison Helpline immediately.