The majority of the calls we receive are about domestic pets but we do occasionally get calls regarding wildlife, this includes hedgehogs.
Metaldehyde is used to control garden snails and slugs, and is the active ingredient in many products. It is available in small blue green pellets for scattering around plants. Hedgehogs can eat these pellets or ingest the slugs/snails which have eaten the pellets.
If you think a hedgehog has been exposed to a toxin please contact your local veterinary clinic or local wildlife rehabilitator.