The adder is Britain's only venomous snake and is in serious decline across much of its range. Conservation welfare considerations include habitat loss, illegal killing, persecution, and the welfare implications of envenomation in wildlife and domestic animals.
Individual adder welfare is threatened by illegal persecution - direct killing motivated by fear - and by habitat loss that fragments populations and limits access to basking and hibernation sites. From a broader welfare perspective, the decline of a native species from its evolutionary niche represents a form of population-level suffering. Adder envenomation of dogs causes real veterinary welfare concerns that are best addressed through awareness and prompt treatment rather than snake persecution. Adders are not aggressive and avoid confrontation - most bites result from accidental contact.