Wild Hedgehog Garden Chemical Exposure Welfare

Hedgehogs in gardens face welfare threats from pesticides, slug pellets, garden chemicals, and other human-applied substances that cause poisoning, secondary toxicity, and habitat degradation.

Key Facts

Hedgehog populations have declined by around 50% in rural areas and 30% in urban areas since 2000
Methaldehyde-based slug pellets cause muscle spasms and death in hedgehogs that consume them
Ferric phosphate slug pellets are safer for hedgehogs but some evidence suggests welfare impacts
Hedgehogs eat slugs and so can accumulate pesticide loads through secondary poisoning
Garden chemicals including lawn fertilisers, herbicides, and insecticides reduce invertebrate prey availability
Hedgehog mortality from slug pellet poisoning was a key factor in the 2022 UK ban on methaldehyde pellets
Injured hedgehogs are frequently presented to wildlife rehabilitators with signs of chemical exposure

Welfare Considerations

Hedgehogs in gardens face a chemical gauntlet that affects welfare through multiple pathways. Direct poisoning from slug pellets was historically a major cause of hedgehog mortality: methaldehyde causes progressive neurological deterioration including twitching, salivation, and convulsions over hours before death - a prolonged and distressing process. The UK government banned methaldehyde pellets in 2022 following evidence of widespread wildlife mortality. Secondary poisoning presents a more complex and ongoing challenge: hedgehogs eating slugs and earthworms that have themselves ingested pesticides accumulate sublethal and lethal doses of insecticides, fungicides, and rodenticides. Neonicotinoid insecticides used on lawns and garden plants reduce the invertebrate food supply hedgehogs depend on. Rodenticide secondary poisoning affects hedgehogs that scavenge poisoned rodent carcases. The cumulative effects of multiple low-level chemical exposures on hedgehog health are poorly quantified but likely significant. Creating chemical-free garden zones and switching to wildlife-friendly alternatives benefits not just hedgehogs but the entire garden ecosystem.

What You Can Do

Stop using all slug pellets - use physical barriers, copper tape, or biological controls instead
Avoid systemic insecticides that reduce invertebrate prey for hedgehogs
Create compost heaps and log piles to provide natural hedgehog habitat
Learn to identify signs of chemical poisoning in hedgehogs
Contact a local wildlife rehabilitator immediately if you find a sick hedgehog
Advocate for stronger restrictions on garden pesticide sales