Pet Safety / Compounds / Monensin

Is Monensin safe for dogs and cats?

Very high risk for pets

LETHAL. LD50 ~10 mg/kg. Dogs accessing cattle feed is common scenario.

What is monensin?

CAS number
17090-79-8
Molecular formula
C36H62O11
Molecular weight
670.87 g/mol
SMILES
CCC1C(CC2(CC(C(C(O2)CC(C(C3C(CC(O3)C(CC4CC(OC4CC(C1O)C)O)C)C)O)C)O)O)C)C
PubChem CID
441145

Risk for dogs

Very high risk

LETHAL. LD50 ~10 mg/kg. Dogs accessing cattle feed is common scenario.

Risk for cats

Very high risk

LETHAL. Even small amounts of contaminated feed can be fatal.

Regulatory consensus

1 regulatory bodyhas classified Monensin.

AgencyYearClassificationNotes
FDA1975Approved veterinary feed additive (NADA 095-735)

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 monensin

  • Veterinary Medicine

Safer alternatives

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

  • Decoquinate (non-ionophore)
    Trade-offs: Alternative approach; specific tradeoffs depend on application context, scale, and regulatory requirements. Full hazard assessment of alternative recommended before adoption to avoid regrettable substitution.
    Relative cost: 1.2-2×

Frequently asked questions

Is monensin safe for pets?

LETHAL. LD50 ~10 mg/kg. Dogs accessing cattle feed is common scenario.

See Monensin in the pets app

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

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Sources (1)
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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 →