Adder Snakebite in UK Dogs and Horses

Adder envenomation causes significant welfare harm in domestic animals and wildlife in the UK, with treatment protocols improving outcomes for bitten dogs and horses.

Key Facts

The adder is the only venomous snake native to the UK
Dogs are most frequently bitten on the muzzle or legs during spring and summer
Adder venom contains phospholipases and proteases causing local tissue damage and systemic effects
Horses bitten on the muzzle may suffer severe swelling restricting breathing
Antivenom, when available, significantly improves outcomes particularly for severe envenomation
Adders are protected under the Wildlife and Countryside Act; killing them is illegal

Welfare Considerations

Adder envenomation causes significant acute welfare harm through local tissue destruction, swelling, pain, and systemic effects including hypotension and cardiovascular compromise in severe cases. Untreated severe cases can cause limb necrosis, multi-organ failure, and death. Horses bitten on the muzzle face a respiratory emergency from soft tissue swelling. Prompt veterinary treatment with appropriate supportive care, and antivenom when available and indicated, dramatically improves outcomes. The protected status of adders means that prevention focuses on management of domestic animals in adder habitat rather than control of the snakes.

What You Can Do

Seek emergency veterinary care immediately for any animal suspected of adder envenomation
Keep dogs on leads in heathland and moorland habitats where adders are active in spring and summer
Never attempt to handle or kill an adder; they are legally protected and will bite defensively
Inform your vet that adder envenomation is suspected rather than just snake bite to guide treatment
Support wildlife rehabilitation centres that treat adder-bitten wildlife