If your dog or cat ate a bait block, pellets, or a bait station labeled bromethalin, call your veterinarian or an animal poison control center now, even if your pet seems fine. Vomiting is most useful within the first few hours. Use the bromethalin calculator to estimate the dose from the label and the amount missing.
Enter weight and amount to get an urgency level and next steps.
What to do right now
- Move your pet away and collect any remaining bait and the package.
- Find the active ingredient and its percent on the label (most bromethalin baits are 0.01%). Take a photo.
- Estimate how much is missing and note the time and your pet's weight.
- Call your veterinarian or an animal poison control center now.
- Do not make your pet vomit unless a professional tells you to, and never if your pet is wobbly, trembling, or sleepy.
- Go to the vet even if your pet seems normal. Signs can be delayed for days.
How much bromethalin is toxic?
Merck Veterinary Manual states that toxic doses are widely accepted at one tenth of the lowest reported LD50. That gives about 0.24 mg of bromethalin per kg for dogs and about 0.04 mg per kg for cats. A 0.01% bait contains 0.1 mg of bromethalin per gram.
| Pet | Toxic dose (0.01% bait) | Lowest LD50 (0.01% bait) |
|---|---|---|
| 10 lb (4.5 kg) cat | about 1.8 g of bait | about 18 g of bait |
| 10 lb (4.5 kg) dog | about 10.8 g | about 108 g |
| 30 lb (13.6 kg) dog | about 32 g | about 324 g |
| 60 lb (27.2 kg) dog | about 65 g | about 647 g |
These are math examples from the Merck figures, not safe amounts. An ASPCA Animal Poison Control Center brief notes that severe poisoning has been reported at doses below the LD50, and bait blocks differ in size between brands. Use the calculator for your pet's weight and the label strength.
Why there is no antidote
Bromethalin is converted in the body to a compound that stops brain and nerve cells from making energy. Fluid builds up in the brain and spinal cord. Vitamin K1, which treats anticoagulant rat poisons, does nothing for bromethalin (Pet Poison Helpline). Vets can only remove as much as possible early and support the brain while the body recovers. That is why every bromethalin ingestion is treated as an emergency.
Symptoms to watch for
- Wobbly walking or weakness in the back legs
- Muscle tremors or twitching
- Overexcitement, or unusual depression and dullness
- Seizures
- High body temperature
- Paralysis
In dogs, larger doses can cause tremors and seizures within 4 to 36 hours. Smaller doses can cause weakness and paralysis 1 to 5 days later. Cats usually develop the slower paralytic form at any dose (Merck Veterinary Manual).
Go straight to an emergency vet if
- Your pet ate any bromethalin bait and it has been less than a few hours
- Your pet is a cat, or a small dog, puppy, or kitten
- Your pet shows any wobbliness, tremors, weakness, or seizures
- You cannot tell how much bait is missing
What the vet will do
If the ingestion was within about 4 hours and your pet has no signs, the vet will usually induce vomiting and give activated charcoal, often in several doses. Because repeated charcoal can raise blood sodium, vets check sodium levels during treatment (Today's Veterinary Practice, ASPCA APCC). Pets with signs may need IV fluids, medicines to reduce brain swelling, seizure control, and hospital care that can last days.
How to prevent it
- Use traps or pest control methods that do not rely on poison where pets live.
- If bait is used, keep it in tamper-resistant stations in places pets cannot reach, and remember that rodents can carry bait out.
- Keep the product package or a photo of the label so you know the active ingredient.
- Ask pest control companies which product they use.
Related: My dog ate rat poison covers all rodenticide types, and the rat and mouse poison calculator helps when the type is unknown. For a room-by-room list, see the pet poison-proofing checklist.
Enter weight and amount to get an urgency level and next steps.
Frequently asked questions
Is there an antidote for bromethalin?
No. Unlike anticoagulant rat poisons, bromethalin is not treated with vitamin K1 and has no antidote. Treatment is early decontamination (vomiting and activated charcoal) and supportive care to reduce brain swelling, which is why the first few hours matter so much.
How much bromethalin is toxic to a dog?
Merck Veterinary Manual says toxic doses are widely accepted at one tenth of the lowest reported LD50. For dogs that is about 0.24 mg of bromethalin per kg. With a 0.01% bait (0.1 mg per gram), that is about 2.4 g of bait per kg, or roughly 11 g for a 10 lb dog.
How much bromethalin is toxic to a cat?
Cats are much more sensitive. Their LD50 is 0.4 to 0.71 mg per kg, so the toxic dose is about 0.04 mg per kg. For a 10 lb cat that is under 2 g of a 0.01% bait, a small fraction of one block.
When do symptoms of bromethalin poisoning start?
Signs can start within hours or be delayed up to 7 days. Large doses in dogs can cause tremors and seizures within 4 to 36 hours; smaller doses can cause weakness and paralysis 1 to 5 days later. Pets can look normal at first.
My pet ate rat poison but I do not know which kind. What now?
Call poison control and bring the package. Bromethalin, anticoagulants, cholecalciferol, and zinc phosphide are treated in completely different ways, and the active ingredient is printed on the label. The rat and mouse poison calculator walks through each type.