Pet Safety / Compounds / Difethialone

Is Difethialone safe for dogs and cats?

Extreme risk for pets

Difethialone follows the same SGAR toxicity profile in dogs — extreme; half-life in dogs estimated at 90+ days. Clinical presentation and treatment are identical to brodifacoum and bromadiolone: delayed hemorrhagic syndrome appearing 3–7 days post-ingestion; vitamin K1 for 4–6 weeks; INR recheck 48–72 hours after cessation of K1. The product Generation is registered for professional PCO use only (consistent with EPA 2011 SGAR restrictions); accidental pet exposure occurs when applicators place blocks in locations accessible to pets, or through rodent secondary toxicosis.

What is difethialone?

The IUPAC name is 3-[3-[4-(4-bromophenyl)phenyl]-1,2,3,4-tetrahydronaphthalen-1-yl]-2-hydroxythiochromen-4-one.

Also known as: 3-[3-[4-(4-bromophenyl)phenyl]-1,2,3,4-tetrahydronaphthalen-1-yl]-2-hydroxythiochromen-4-one, Difethiaro, Baraki;LM 2219, Difethialone 10 microg/mL in Acetonitrile.

IUPAC name
3-[3-[4-(4-bromophenyl)phenyl]-1,2,3,4-tetrahydronaphthalen-1-yl]-2-hydroxythiochromen-4-one
CAS number
104653-34-1
Molecular formula
C31H23BrO2S
Molecular weight
539.5 g/mol
SMILES
C1C(CC2=CC=CC=C2C1C3=C(SC4=CC=CC=C4C3=O)O)C5=CC=C(C=C5)C6=CC=C(C=C6)Br
PubChem CID
91771

Risk for dogs

Extreme risk

Difethialone follows the same SGAR toxicity profile in dogs — extreme; half-life in dogs estimated at 90+ days. Clinical presentation and treatment are identical to brodifacoum and bromadiolone: delayed hemorrhagic syndrome appearing 3–7 days post-ingestion; vitamin K1 for 4–6 weeks; INR recheck 48–72 hours after cessation of K1. The product Generation is registered for professional PCO use only (consistent with EPA 2011 SGAR restrictions); accidental pet exposure occurs when applicators place blocks in locations accessible to pets, or through rodent secondary toxicosis.

Risk for cats

Extreme risk

Extreme toxicity via VKOR inhibition with prolonged half-life; secondary relay toxicosis through prey is the primary cat exposure route. Hemothorax and systemic hemorrhage presentations. Treatment: vitamin K1 for 4–6 weeks.

Regulatory consensus

1 regulatory bodyhas classified Difethialone.

AgencyYearClassificationNotes
Unknown——

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 difethialone

  • Industrial Facilities — Manufacturing plants, Chemical storage areas, Waste treatment sites
  • Occupational Environments — Factories, Warehouses, Transportation vehicles

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Difethialone:

  • Integrated Pest Management (IPM); Biopesticides; Physical controls
    Trade-offs: Combines biological, cultural, and targeted chemical controls; reduces overall chemical use 30-70%; requires trained practitioners and monitoring infrastructure; higher management complexity; proven effective at scale in many crop systems.
    Relative cost: 1.2-2×

Frequently asked questions

Is difethialone safe for pets?

Difethialone follows the same SGAR toxicity profile in dogs — extreme; half-life in dogs estimated at 90+ days. Clinical presentation and treatment are identical to brodifacoum and bromadiolone: delayed hemorrhagic syndrome appearing 3–7 days post-ingestion; vitamin K1 for 4–6 weeks; INR recheck 48–72 hours after cessation of K1. The product Generation is registered for professional PCO use only (consistent with EPA 2011 SGAR restrictions); accidental pet exposure occurs when applicators place blocks in locations accessible to pets, or through rodent secondary toxicosis.

What products contain difethialone?

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

See Difethialone in the pets app

Look up products containing difethialone, compare to alternatives, and explore the full data record.

Open in pets View raw API data

Sources (2)
  1. US EPA: Second-Generation Anticoagulant Rodenticides (SGARs) — Risk Mitigation Decision; brodifacoum, bromadiolone, difethialone, difenacoum; non-target wildlife secondary poisoning; restriction to certified pest control operators; tamper-resistant bait stations; consumer product phase-out (2011) (2011) — regulatory
  2. ASPCA Animal Poison Control Center: Rodenticide Toxicosis in Dogs and Cats — anticoagulant SGARs/FGARs; bromethalin; cholecalciferol; zinc phosphide; vitamin K1 dosing; decontamination windows; INR monitoring; prognosis by rodenticide class (2023) (2023) — veterinary

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 →