Rat Poison Toxicity Calculator for Dogs
ASPCA APCC advises decontaminating and monitoring any dog that ate more than 0.02 mg/kg of brodifacoum (one-tenth of its lowest reported LD50), and Merck applies the same one-tenth rule to other rodenticides, so any rat poison ingestion means calling your vet now. (ASPCA APCC; Merck Veterinary Manual)
Rat poison toxicity calculator
Educational estimate from published toxicology references. Not veterinary advice. If in doubt, call your vet.
Risk level (example)
Emergency
Estimated dose: 0.037 mg/kg
Reported dog LD50 for brodifacoum: 0.2–4 mg/kg. Toxic dose is taken as one-tenth of the lowest LD50 (0.02 mg/kg).
Anticoagulant bleeding signs are often delayed by several days.
Emergency line
ASPCA APCC (888) 426-4435, fee may apply · Pet Poison Helpline (855) 764-7661, fee may apply
- Go to the nearest emergency vet now and call ahead.
- Bring the package or a photo of the label (active ingredient and EPA reg. number).
- Do not induce vomiting unless a veterinarian tells you to.
How thresholds are set: ASPCA APCC lists dog LD50s of 0.2–4 mg/kg for brodifacoum, 11–15 mg/kg for bromadiolone and 0.9–8 mg/kg for diphacinone, and advises decontaminating and monitoring any dog above 0.02 mg/kg of brodifacoum. Merck notes toxic doses are taken as one-tenth of the lowest reported LD50, and lists a dog bromethalin LD50 of 2.38–5.6 mg/kg, with a convulsant syndrome at or above about 3.54 mg/kg and a paralytic syndrome at lower doses. Bait concentration comes from the package label. Any rodenticide ingestion means calling your vet now.
Source: ASPCA APCC — Deadly for pests, dangerous for pets (rodenticides); Merck Veterinary Manual — anticoagulant rodenticide poisoning
Educational estimate from published toxicology references. Not veterinary advice. If in doubt, call your vet.
Result tiers and what to do now
Call your vet now — Any rodenticide, below one-tenth of the lowest LD50
Call your vet or a poison hotline now, even if your dog seems fine; signs can take days. Keep the package and EPA registration number. (ASPCA APCC)
Emergency — ≥ one-tenth of the lowest LD50 (e.g. 0.02 mg/kg brodifacoum), or unknown ingredient
Go to the nearest emergency vet now and bring the package. Merck reports a bromethalin convulsant syndrome at or above about 3.54 mg/kg. (Merck Veterinary Manual)
Call for help
Call your vet or an emergency clinic. ASPCA Animal Poison Control Center (888) 426-4435 or Pet Poison Helpline (855) 764-7661 (fees may apply). Never induce vomiting without a vet's say-so.
Dose by dog weight
| Dog weight | Brodifacoum 0.005% | Diphacinone 0.005% | Bromadiolone 0.005% | Bromethalin 0.01% |
|---|---|---|---|---|
| 5 lb (2.3 kg) | 0.91 g | 4.08 g | 50 g | 5.40 g |
| 10 lb (4.5 kg) | 1.81 g | 8.16 g | 100 g | 11 g |
| 20 lb (9.1 kg) | 3.63 g | 16 g | 200 g | 22 g |
| 40 lb (18.1 kg) | 7.26 g | 33 g | 399 g | 43 g |
| 80 lb (36.3 kg) | 15 g | 65 g | 798 g | 86 g |
Bait concentration varies — use the percentage on your package. Cholecalciferol (vitamin D3) baits: use the vitamin D calculator. Unknown ingredient: treat as an emergency. Published ranges are not safe allowances.
Frequently asked questions
How much rat poison is toxic to a dog?
It depends on the active ingredient. ASPCA APCC lists dog LD50s of 0.2–4 mg/kg for brodifacoum, 11–15 mg/kg for bromadiolone and 0.9–8 mg/kg for diphacinone; Merck lists 2.38–5.6 mg/kg for bromethalin. Toxic doses are taken as one-tenth of the lowest reported LD50.
How do I find the active ingredient?
Look on the package for the active ingredient and its percentage (for example brodifacoum 0.005%) and the EPA registration number. If you can't find it, bring the package or a photo to the vet and treat it as an emergency.
When do symptoms of rat poison appear?
Anticoagulant bleeding signs are often delayed several days. Merck reports bromethalin convulsions within 4–36 hours at higher doses and a paralytic syndrome 1–5 days after lower doses. Call before signs appear.
What about vitamin D (cholecalciferol) rat bait?
Cholecalciferol baits work differently and are assessed with the vitamin D toxicity calculator.
Full guide: symptoms, timeline, treatment & cost
Cholecalciferol (vitamin D3) bait? Use the vitamin D toxicity calculator
Related calculators
Sources
- ASPCA APCC — Deadly for pests, dangerous for pets (rodenticides)
- Merck Veterinary Manual — anticoagulant rodenticide poisoning
- Merck Veterinary Manual — bromethalin poisoning
- Pet Poison Helpline
Educational estimate from published toxicology references. Not veterinary advice. If in doubt, call your vet.