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Slug Pellets and Dogs: A Toxic UK Garden Danger

Slug pellets are a common sight in UK gardens, but they can be seriously dangerous to dogs. Understanding which types are most hazardous and recognising the signs of poisoning could save your dog's life. Here's what every UK dog owner needs to know.

Metaldehyde Slug Pellets: Banned but Still a Risk

Metaldehyde slug pellets were the traditional garden treatment for slugs and snails in the UK for decades. Due to their toxicity to wildlife (particularly birds, hedgehogs and domestic animals), metaldehyde-based slug pellets were banned in Great Britain from March 2022 under the Control of Pesticides Regulations.

Despite the ban on sale and new supply, old stocks may remain in sheds and garages across the country. Metaldehyde is highly toxic to dogs and cats — ingestion causes tremors, incoordination, hyperthermia, seizures and respiratory failure within 30 minutes to 3 hours.

If your dog shows sudden tremors, uncontrollable convulsions or hyperthermia after garden access, consider metaldehyde poisoning and go to an emergency vet immediately. Treatment involves inducing vomiting (if early), anti-seizure medication, cooling, intravenous fluids and intensive monitoring.

Ferric Phosphate Slug Pellets: Less Toxic but Not Safe

Ferric phosphate is now the primary active ingredient in UK slug pellets since the metaldehyde ban. It's marketed as 'wildlife-friendly' or 'safe for pets', but this designation requires qualification — ferric phosphate pellets are significantly less acutely toxic than metaldehyde, but they are not entirely safe for pets.

In dogs, ingestion of large quantities of ferric phosphate pellets can cause vomiting, diarrhoea and lethargy. The iron component can cause iron toxicity in large amounts. Clinical signs are much less dramatic than metaldehyde poisoning and most dogs recover with supportive care.

Some ferric phosphate slug pellets also contain EDTA (ethylenediaminetetraacetic acid) as a stabiliser. There is some evidence that EDTA increases iron absorption and therefore toxicity. Products containing both ferric phosphate and EDTA should be treated with more caution.

Alternative Slug Control for Pet-Friendly Gardens

Several effective slug and snail control methods don't pose risks to pets. Copper tape (placed around pots and raised beds) creates an electrical deterrent for slugs without any chemical hazard. Beer traps (shallow containers sunk into the ground and filled with beer) attract and drown slugs without chemical risk to pets, though the traps themselves should be secured to prevent dogs drinking the contents.

Encouraging natural predators is one of the most effective long-term approaches — hedgehogs, ground beetles, toads and birds all eat slugs. Creating a hedgehog-friendly garden therefore also reduces your slug population.

Nematodes — microscopic parasitic organisms applied to the soil as a biological control — are safe for pets, children and wildlife and highly effective against slugs. Available from garden centres and online, they require moist soil and warm temperatures to work effectively.

Signs That Your Dog Has Eaten Slug Pellets

For metaldehyde (if old stock is present): expect rapid onset of tremors, ataxia (loss of coordination), hyperthermia (the body overheats), convulsions and potential respiratory failure. Onset is typically within 30–60 minutes of ingestion. This is an emergency.

For ferric phosphate: expect vomiting, diarrhoea, drooling and lethargy. Symptoms typically appear within a few hours. Severity depends on quantity ingested relative to body weight. Contact a vet for advice on whether the animal needs to be seen.

For either type: if you know or strongly suspect ingestion, contact your vet or Animal Poison Line (01202 509000) immediately. If possible, bring the product packaging to the vet appointment — knowing the active ingredient and the concentration helps guide treatment.

Prevention and Garden Safety

The simplest prevention is not using slug pellets in gardens where dogs have access. If you do use ferric phosphate pellets, apply them according to label instructions (thinly scattered rather than piled), ideally in the evening when dogs are less likely to be in the garden, and water them in if possible to reduce surface visibility.

Store all garden chemicals in locked cupboards inaccessible to pets. Dispose of any old metaldehyde slug pellet stocks through your local hazardous waste facility — do not put them in standard household waste bins.

Check your garden for any pellets after applying them and particularly after rain, which can concentrate them. Monitor your dog for any signs of nausea or disorientation after garden access during slug pellet season (spring and autumn, when slug activity is highest).

Find a Vet Near You

Slug pellet poisoning — particularly metaldehyde — is an emergency. Know your nearest emergency vet before you need one. Use CompareMyVet at app.comparemyvet.uk to find and compare vet practices and out-of-hours emergency services near you.