Pet Safety / Compounds / Fluralaner (Bravecto)

Is Fluralaner (Bravecto) safe for dogs and cats?

Moderate risk for pets

Fluralaner presents a moderate risk to dogs, driven by the class-wide FDA-required neurological adverse event warning for isoxazoline ectoparasiticides. In the vast majority of dogs, Bravecto (fluralaner) is well-tolerated and provides excellent 12-week flea and tick protection from a single dose — a major practical advantage for compliance. However, FDA pharmacovigilance data identified a subset of dogs developing neurological adverse events (muscle tremors, ataxia, seizures) during or after isoxazoline treatment, including some dogs without prior history of neurological disease. Dogs with pre-existing epilepsy, known seizure disorders, or neurological conditions are at higher risk and should use isoxazolines only under veterinary guidance with informed owner consent. The long half-life (~12–15 days; effects persist for weeks after a single dose) means that if neurological adverse events develop, the drug cannot be rapidly eliminated. Veterinary monitoring for the first 24–48 hours after the first dose is advisable in high-risk dogs.

What is fluralaner (bravecto)?

The IUPAC name is 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-1,2-oxazol-3-yl]-2-methyl-N-[2-oxo-2-(2,2,2-trifluoroethylamino)ethyl]benzamide.

Also known as: 4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-1,2-oxazol-3-yl]-2-methyl-N-[2-oxo-2-(2,2,2-trifluoroethylamino)ethyl]benzamide, Fluralaner, Bravecto, AH252723.

IUPAC name
4-[5-(3,5-dichlorophenyl)-5-(trifluoromethyl)-4H-1,2-oxazol-3-yl]-2-methyl-N-[2-oxo-2-(2,2,2-trifluoroethylamino)ethyl]benzamide
CAS number
864731-61-3
Molecular formula
C22H17Cl2F6N3O3
Molecular weight
556.3 g/mol
SMILES
CC1=C(C=CC(=C1)C2=NOC(C2)(C3=CC(=CC(=C3)Cl)Cl)C(F)(F)F)C(=O)NCC(=O)NCC(F)(F)F
PubChem CID
25144319

Risk for dogs

Moderate risk

Fluralaner presents a moderate risk to dogs, driven by the class-wide FDA-required neurological adverse event warning for isoxazoline ectoparasiticides. In the vast majority of dogs, Bravecto (fluralaner) is well-tolerated and provides excellent 12-week flea and tick protection from a single dose — a major practical advantage for compliance. However, FDA pharmacovigilance data identified a subset of dogs developing neurological adverse events (muscle tremors, ataxia, seizures) during or after isoxazoline treatment, including some dogs without prior history of neurological disease. Dogs with pre-existing epilepsy, known seizure disorders, or neurological conditions are at higher risk and should use isoxazolines only under veterinary guidance with informed owner consent. The long half-life (~12–15 days; effects persist for weeks after a single dose) means that if neurological adverse events develop, the drug cannot be rapidly eliminated. Veterinary monitoring for the first 24–48 hours after the first dose is advisable in high-risk dogs.

Regulatory consensus

1 regulatory bodyhas classified Fluralaner (Bravecto).

AgencyYearClassificationNotes
IARC2022Not evaluated by IARC — fluralaner (Bravecto; MSD Animal Health/Merck Animal Health) is an FDA/CVM-approved isoxazoline ectoparasiticide for dogs and cats providing 12-week (dogs) or 8–12-week (cats) protection against fleas and ticks; FDA label carries a neurological adverse event warning (boxed warning or paragraph caution); no carcinogenicity classification

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where pets encounter fluralaner (bravecto)

  • Industrial FacilitiesManufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational EnvironmentsFactories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Fluralaner (Bravecto):

  • Alternative drug class; Non-pharmacological therapy; Lowest effective dose
    Trade-offs: Direct chemical substitution requires verification that the replacement does not introduce new hazards (regrettable substitution). Conduct full hazard assessment of proposed alternative before adoption.
    Relative cost: 1.2-2×

Frequently asked questions

Is fluralaner (bravecto) safe for pets?

Fluralaner presents a moderate risk to dogs, driven by the class-wide FDA-required neurological adverse event warning for isoxazoline ectoparasiticides. In the vast majority of dogs, Bravecto (fluralaner) is well-tolerated and provides excellent 12-week flea and tick protection from a single dose — a major practical advantage for compliance. However, FDA pharmacovigilance data identified a subset of dogs developing neurological adverse events (muscle tremors, ataxia, seizures) during or after isoxazoline treatment, including some dogs without prior history of neurological disease. Dogs with pre-existing epilepsy, known seizure disorders, or neurological conditions are at higher risk and should use isoxazolines only under veterinary guidance with informed owner consent. The long half-life (~12–15 days; effects persist for weeks after a single dose) means that if neurological adverse events develop, the drug cannot be rapidly eliminated. Veterinary monitoring for the first 24–48 hours after the first dose is advisable in high-risk dogs.

What products contain fluralaner (bravecto)?

Fluralaner (Bravecto) appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).

See Fluralaner (Bravecto) in the pets app

Look up products containing fluralaner (bravecto), compare to alternatives, and explore the full data record.

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Sources (1)

  1. Fluralaner Bravecto MSD Animal Health FDA CVM; Isoxazoline GABA Chloride Channel Antagonist; 12-Week Duration Single Dose; FDA Neurological Adverse Event Warning 2018 2022 Tremors Ataxia Seizures; GABA-A Invertebrate Selectivity; Long Half-Life 12-15 Days Lipophilic Adipose; Bravecto Chewable Spot-On; Pharmacovigilance Post-Marketing; Aquatic Invertebrate Daphnia Ecotoxicity; IARC Not Evaluated (2022) — regulatory

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →