Metaldehyde is the traditional slug and snail poison that has been used since the 1940s. Highly effective but carries serious risks to dogs, cats, and wildlife. Being phased out in the UK and EU in favor of safer iron phosphate alternatives.
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Classification
Molluscicide (Aldehyde)
Signal Word
Caution to Warning
Mode of Action
Neurotoxin: causes excessive mucus secretion, dehydration, and seizures in mollusks
Slugs and snails. Metaldehyde is highly specific to gastropod mollusks. Does not affect earthworms, insects, or other soil organisms directly, though secondary poisoning of beetle predators that eat poisoned slugs has been documented.
Products and Brand Names
Deadline M-Ps (slug pellets), Corry Slug and Snail Killer (metaldehyde version), Sluggo (note: Sluggo is iron phosphate NOT metaldehyde - check labels), various store brand slug baits. Always verify active ingredient on label - some brands have switched from metaldehyde to iron phosphate.
Safety and Precautions
Moderate to high toxicity to mammals. EPA toxicity Category II-III depending on formulation.
DOG DANGER: Metaldehyde is one of the most common causes of fatal poisoning in dogs. Dogs are attracted to the pellets and will actively seek them out. As little as 1 teaspoon per 10 lbs of body weight can be fatal. Symptoms include tremors, seizures, hyperthermia, and death within hours. There is NO specific antidote. If your dog ingests metaldehyde bait, rush to emergency vet IMMEDIATELY.
Also toxic to cats, birds, and wildlife. Hedgehog deaths are a major concern in the UK, leading to the ban. If you have pets or wildlife, use iron phosphate bait instead - it is equally effective and completely pet-safe.
Pro Tips
Why iron phosphate is better: Iron phosphate (Sluggo) provides equivalent slug and snail control with zero risk to pets, children, or wildlife. There is no practical reason for homeowners to use metaldehyde when iron phosphate is widely available. The only advantage metaldehyde retains is slightly faster kill speed (hours vs days).
If you must use it: Place pellets under boards, flower pots, or slug shelters where pets cannot access them. Use tamper-resistant bait stations. Apply sparingly - more bait does not mean better control. Water the area first to bring slugs to the surface.
Timing: Apply in late afternoon before slugs become active at night. Reapply after rain as metaldehyde dissolves in water (losing effectiveness but also contaminating soil).
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Follow the product label. Keep pets out of treated areas until completely dried (2–4 hours for sprays). Once dry, treated surfaces pose minimal risk to dogs and cats.
Q: Can I use metaldehyde indoors?
Check the specific product label — formulations vary. Baits and dusts often have indoor labeling; concentrates and granulars are typically outdoor.
Q: How long does metaldehyde last after application?
Residual varies by formulation, surface type, weather, and UV exposure. Indoor applications last longer than outdoor. Check the product label for re-application intervals.
Q: What should I do if exposed?
Remove contaminated clothing, wash skin with soap and water. For eye contact, rinse 15–20 minutes. For ingestion or severe symptoms, call Poison Control (1-800-222-1222). Have the product label available.
📋 Safety Data Sheet (SDS)
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Metaldehyde Slug and Snail Bait — Safety Data Sheet
View the official SDS document for this product directly on the CDMS label database.
Did you know? The UK banned metaldehyde for outdoor use effective 2022 after decades of dog poisonings and concerns about water contamination. The EU is following suit. The US has no current restrictions, but the trend toward iron phosphate is clear.
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Reviewed by Derek GiordanoContent reviewed by a licensed pest management professional. Last reviewed: April 2026.
