Slug Bait poisoning in dogs and cats
Toxic agent: Metaldehyde · Reviewed 2026-08-18
Phone a vet now, before reading on. Have ready: your pet's weight, roughly how much was eaten and when, and the packaging if there is any. ASPCA Animal Poison Control (+1 888 426 4435), Pet Poison Helpline, or Animal PoisonLine in the UK.
Metaldehyde slug pellets cause continuous seizures within an hour, and they are formulated with bran to smell like food. Of the garden chemicals, this is the one that kills fastest.
What it actually does
Metaldehyde lowers the seizure threshold in the central nervous system, probably by reducing GABA and serotonin activity. The result is uncontrollable tremors and convulsions that generate enormous heat — animals die of hyperthermia and the muscle breakdown that follows as much as of the seizures themselves.
How much matters
The margin is narrow and the bait is attractive:
| From about 100 mg/kg | seizures expected in dogs |
|---|---|
| Typical pellets | 1.5–5% metaldehyde |
| Bran carrier | deliberately palatable — pellets are designed to be eaten |
| Ferric phosphate alternatives | much safer, and worth switching to if you have pets |
The name to look for on the box is metaldehyde. Ferric or iron phosphate baits exist, cause mild gastrointestinal upset at most, and are the sensible choice in a garden a dog uses.
What you will see, and when
Onset: 30 minutes to 3 hours. Typical course: 12 to 72 hours, often requiring sedation throughout.
- 30 min – 1 hourAnxiety, drooling, vomiting, muscle twitching
- 1–3 hoursContinuous tremors, then seizures, rapid breathing, temperature climbing above 41 °C
- 3–24 hoursMuscle breakdown, kidney injury from myoglobin, liver damage, respiratory failure
What the vet will do
Seizure control is the priority — methocarbamol, benzodiazepines, and general anaesthesia if needed. Active cooling for hyperthermia, gastric lavage under anaesthesia, intravenous lipid emulsion, fluids to protect the kidneys. Animals often need sedation for a day or more. No antidote.
Outlook
Good if seizures are controlled early and hyperthermia is prevented. Poor once temperature and muscle breakdown are established.
Dogs and cats are not the same here
Both, dogs far more often because the bran carrier appeals to them.
Where it comes from in a normal house
- Blue or green pellets scattered on garden beds
- Open boxes in sheds and greenhouses
- Allotments and neighbouring gardens
- Liquid and gel slug killers
The thing people get wrong
“Pet-safe is on the box, so it is fine.”
Pet-safe on slug bait usually means ferric phosphate rather than metaldehyde — but the claim is marketing, not a standard. Read the active ingredient. If it says metaldehyde, it is not pet safe at any dose.
PawLife keeps your pet's weight, medication and feeding history in one place, so when you make this call you can answer the vet's questions in seconds. The full food safety database is free.
Get PawLife on the App StoreFrequently asked questions
How much Slug Bait is dangerous?
The name to look for on the box is metaldehyde. Ferric or iron phosphate baits exist, cause mild gastrointestinal upset at most, and are the sensible choice in a garden a dog uses.
How long after exposure to Slug Bait do symptoms start?
30 minutes to 3 hours. Anxiety, drooling, vomiting, muscle twitching. 12 to 72 hours, often requiring sedation throughout.
Is Slug Bait worse for cats or dogs?
Both, dogs far more often because the bran carrier appeals to them.
Is it true that: Pet-safe is on the box, so it is fine.
Pet-safe on slug bait usually means ferric phosphate rather than metaldehyde — but the claim is marketing, not a standard. Read the active ingredient. If it says metaldehyde, it is not pet safe at any dose.
Related emergencies
Sources
This page is information, not veterinary advice. Toxic doses vary with body weight, age, breed and individual sensitivity, and the figures above exist to explain what a vet is assessing, never to decide that an amount is safe. If you are reading this because something has already been eaten, call a vet.