Is Paraquat safe for dogs and cats?
High risk for petsDogs can be poisoned by walking through freshly treated fields and grooming their paws/fur, by drinking from paraquat-contaminated water sources, or by direct accidental ingestion. Canine paraquat toxicity produces the same pulmonary fibrosis syndrome as in humans; the small dog's lower body weight makes ingestion of even small amounts (licking treated grass) potentially lethal. Clinical progression: initial vomiting and diarrhea, followed by worsening respiratory distress over 24–72 hours as pulmonary fibrosis develops. No effective antidote; aggressive supportive care and avoidance of supplemental O₂ (O₂ accelerates radical generation) are the mainstays of treatment. Prognosis grave with significant ingestion.
What is paraquat?
The IUPAC name is 1-methyl-4-(1-methylpyridin-1-ium-4-yl)pyridin-1-ium.
Also known as: 1-methyl-4-(1-methylpyridin-1-ium-4-yl)pyridin-1-ium, Paraquat ion, Paraquat dication, 1,1'-Dimethyl-4,4'-bipyridinium.
- IUPAC name
- 1-methyl-4-(1-methylpyridin-1-ium-4-yl)pyridin-1-ium
- CAS number
- 4685-14-7
- Molecular formula
- C12H14N2+2
- Molecular weight
- 186.25 g/mol
- SMILES
- C[N+]1=CC=C(C=C1)C2=CC=[N+](C=C2)C
- PubChem CID
- 15939
Risk for dogs
High riskDogs can be poisoned by walking through freshly treated fields and grooming their paws/fur, by drinking from paraquat-contaminated water sources, or by direct accidental ingestion. Canine paraquat toxicity produces the same pulmonary fibrosis syndrome as in humans; the small dog's lower body weight makes ingestion of even small amounts (licking treated grass) potentially lethal. Clinical progression: initial vomiting and diarrhea, followed by worsening respiratory distress over 24–72 hours as pulmonary fibrosis develops. No effective antidote; aggressive supportive care and avoidance of supplemental O₂ (O₂ accelerates radical generation) are the mainstays of treatment. Prognosis grave with significant ingestion.
Risk for cats
High riskCats face similar exposure routes as dogs (paw-grooming after walking through treated areas, drinking contaminated water). Cats may be at higher risk due to their meticulous grooming behavior. The acute and delayed pulmonary toxicity mechanism is identical to other species. Additionally, cats' limited hepatic conjugation capacity may affect paraquat elimination. ASPCA APCC treats paraquat as a major toxin of concern in companion animals. Any suspected paraquat ingestion in a cat warrants immediate emergency veterinary evaluation.
Regulatory consensus
11 regulatory and scientific bodies have classified Paraquat. The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | — | Not classified as a carcinogen | Explicit statement in safety summary |
| EU | 2007 | Banned | |
| UK | — | Banned | |
| US EPA | — | Registered for restricted use | Still registered in the US for restricted use by licensed applicators on farms |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: None, 2 positive / 1 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: None, 2 positive / 1 negative reports) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 1 (score: very high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Category 1A-1C (score: very high) | |
| EPA CTX / Skin-Eye | — | Skin Sensitization: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | Eye Irritation: Category 6.4A (Category 2A) (score: high) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Category 6.3A (Category 2) (score: high) |
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 paraquat
- 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 Paraquat:
-
Physical/mechanical pest control (IPM)
Trade-offs: More labor-intensive. May not be sufficient for severe infestations.Relative cost: 1.2-2×
Frequently asked questions
Is paraquat safe for pets?
Dogs can be poisoned by walking through freshly treated fields and grooming their paws/fur, by drinking from paraquat-contaminated water sources, or by direct accidental ingestion. Canine paraquat toxicity produces the same pulmonary fibrosis syndrome as in humans; the small dog's lower body weight makes ingestion of even small amounts (licking treated grass) potentially lethal. Clinical progression: initial vomiting and diarrhea, followed by worsening respiratory distress over 24–72 hours as pulmonary fibrosis develops. No effective antidote; aggressive supportive care and avoidance of supplemental O₂ (O₂ accelerates radical generation) are the mainstays of treatment. Prognosis grave with significant ingestion.
What products contain paraquat?
Paraquat appears in: Manufacturing plants (Industrial facilities); Chemical storage areas (Industrial facilities); Factories (Occupational environments); Warehouses (Occupational environments).
Why do regulators disagree about paraquat?
Paraquat has been classified by 11 agencies including IARC, EU, UK, US EPA, EPA CTX / Genetox, with differing conclusions. 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. See the regulatory consensus table on this page for the full picture.
See Paraquat in the pets app
Look up products containing paraquat, compare to alternatives, and explore the full data record.
Open in pets View raw API dataSources (3)
- WHO Specifications and Evaluations for Public Health Pesticides: Paraquat Dichloride (2016) — regulatory
- US EPA Reregistration Eligibility Decision (RED) for Paraquat Dichloride (1997) — regulatory
- ASPCA Animal Poison Control Center: Paraquat Toxicosis in Companion Animals (2020) — report
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 →