Pet Safety / Compounds / Ptaquiloside

Is Ptaquiloside safe for dogs and cats?

Moderate risk for pets

Bracken fern ingestion uncommon in dogs; chronic exposure causes bone marrow suppression (thiaminase effect + ptaquiloside toxicity).

What is ptaquiloside?

The IUPAC name is methyl (1R,2S,3R,6R,8R,13S,14R,15R,16S,17S)-10,15,16-trihydroxy-9,13-dimethyl-3-(3-methylbut-2-enoyloxy)-4,11-dioxo-5,18-dioxapentacyclo[12.5.0.01,6.02,17.08,13]nonadec-9-ene-17-carboxylate.

Also known as: Brusatol, Yatansin, 3ATY6SZ64B, methyl (1R,2S,3R,6R,8R,13S,14R,15R,16S,17S)-10,15,16-trihydroxy-9,13-dimethyl-3-(3-methylbut-2-enoyloxy)-4,11-dioxo-5,18-dioxapentacyclo[12.5.0.01,6.02,17.08,13]nonadec-9-ene-17-carboxylate.

IUPAC name
methyl (1R,2S,3R,6R,8R,13S,14R,15R,16S,17S)-10,15,16-trihydroxy-9,13-dimethyl-3-(3-methylbut-2-enoyloxy)-4,11-dioxo-5,18-dioxapentacyclo[12.5.0.01,6.02,17.08,13]nonadec-9-ene-17-carboxylate
CAS number
87625-62-5
Molecular formula
C20H30O8
Molecular weight
398.45 g/mol
SMILES
CC1=C(C(=O)CC2(C1CC3C45C2C(C(C(C4C(C(=O)O3)OC(=O)C=C(C)C)(OC5)C(=O)OC)O)O)C)O
PubChem CID
73432

Risk for dogs

Moderate risk

Bracken fern ingestion uncommon in dogs; chronic exposure causes bone marrow suppression (thiaminase effect + ptaquiloside toxicity).

Risk for cats

Moderate risk

Rarely exposed; would show similar bone marrow and bladder effects as cattle if chronically exposed.

Regulatory consensus

1 regulatory bodyhas classified Ptaquiloside.

AgencyYearClassificationNotes
IARC1987Group 2B — Possibly carcinogenic (bracken fern, 1987; ptaquiloside specifically listed as the active carcinogen)

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 ptaquiloside

  • Natural Product
  • Food Contaminant

Safer alternatives

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

  • Avoid bracken fern consumption
    Trade-offs: Bracken (Pteridium aquilinum) is consumed as vegetable in Japan (warabi) and Korea (gosari). Blanching reduces but doesn't eliminate ptaquiloside.
    Relative cost: N/A

Frequently asked questions

Is ptaquiloside safe for pets?

Bracken fern ingestion uncommon in dogs; chronic exposure causes bone marrow suppression (thiaminase effect + ptaquiloside toxicity).

See Ptaquiloside in the pets app

Look up products containing ptaquiloside, 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 →