Pet Safety / Compounds / Homoanatoxin-a

Is Homoanatoxin-a safe for dogs and cats?

Moderate risk for pets

Dogs are the primary sentinel species for homoanatoxin-a toxicity globally. Numerous documented deaths in dogs have occurred from ingestion of Phormidium/Oscillatoria benthic mats in rivers and streams in New Zealand, the United Kingdom, Scotland, and Ireland. Dogs actively investigate and mouth river-bottom substrate, directly ingesting the dense biofilms. Clinical presentation after homoanatoxin-a ingestion: rapid-onset muscle tremors, weakness, loss of coordination, respiratory distress, and death — typically within 15–30 minutes of ingestion of a lethal dose. There is no specific antidote; supportive care (artificial ventilation) may be attempted if the dog is found rapidly. Dog owners in regions with known mat-forming cyanobacteria in rivers should keep dogs leashed and away from river beds and should monitor for brown/orange biofilm mats. Environmental monitoring by water authorities in New Zealand in particular includes homoanatoxin-a as part of river cyanotoxin surveillance.

What is homoanatoxin-a?

CAS number
73386-73-9
Molecular formula
C11H17NO
Molecular weight
179.26 g/mol
SMILES
CCC(=O)C1=CCCC2CCC1N2
PubChem CID
126727

Risk for dogs

Moderate risk

Dogs are the primary sentinel species for homoanatoxin-a toxicity globally. Numerous documented deaths in dogs have occurred from ingestion of Phormidium/Oscillatoria benthic mats in rivers and streams in New Zealand, the United Kingdom, Scotland, and Ireland. Dogs actively investigate and mouth river-bottom substrate, directly ingesting the dense biofilms. Clinical presentation after homoanatoxin-a ingestion: rapid-onset muscle tremors, weakness, loss of coordination, respiratory distress, and death — typically within 15–30 minutes of ingestion of a lethal dose. There is no specific antidote; supportive care (artificial ventilation) may be attempted if the dog is found rapidly. Dog owners in regions with known mat-forming cyanobacteria in rivers should keep dogs leashed and away from river beds and should monitor for brown/orange biofilm mats. Environmental monitoring by water authorities in New Zealand in particular includes homoanatoxin-a as part of river cyanotoxin surveillance.

Regulatory consensus

1 regulatory bodyhas classified Homoanatoxin-a.

AgencyYearClassificationNotes
WHO (cyanotoxin guidelines for safe recreational water use and drinking water quality, 2020)2020no carcinogenicity classification; potent nicotinic acetylcholine receptor agonist; neurotoxic cyanotoxin from Oscillatoria/Phormidium; responsible for dog and livestock deaths from stream biofilm ingestion; no established regulatory limit in most jurisdictions; not classified for carcinogenicity by IARC, NTP, EFSA, or US EPA

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 homoanatoxin-a

  • 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 Homoanatoxin-a:

  • Avoidance (no chemical substitute)
    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 homoanatoxin-a safe for pets?

Dogs are the primary sentinel species for homoanatoxin-a toxicity globally. Numerous documented deaths in dogs have occurred from ingestion of Phormidium/Oscillatoria benthic mats in rivers and streams in New Zealand, the United Kingdom, Scotland, and Ireland. Dogs actively investigate and mouth river-bottom substrate, directly ingesting the dense biofilms. Clinical presentation after homoanatoxin-a ingestion: rapid-onset muscle tremors, weakness, loss of coordination, respiratory distress, and death — typically within 15–30 minutes of ingestion of a lethal dose. There is no specific antidote; supportive care (artificial ventilation) may be attempted if the dog is found rapidly. Dog owners in regions with known mat-forming cyanobacteria in rivers should keep dogs leashed and away from river beds and should monitor for brown/orange biofilm mats. Environmental monitoring by water authorities in New Zealand in particular includes homoanatoxin-a as part of river cyanotoxin surveillance.

What products contain homoanatoxin-a?

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

See Homoanatoxin-a in the pets app

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Sources (1)

  1. WHO Cyanotoxin Guidelines Safe Recreational Water Drinking Water Quality 2020: Homoanatoxin-a Oscillatoria Phormidium Benthic Mats nAChR Agonist; Dog Deaths NZ Scotland; No Established Regulatory Limit; No Carcinogenicity Classification (2020) — 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 →