My dog was bitten by an adder – what should I do?

Updated 2026-09-30 · 2 sources

Based on: Animal PoisonLine (UK, VPIS), Lervik et al., 53 Swedish dogs bitten by Vipera berus, Acta Vet Scand 2010

Call a vet now

Call your vet or the nearest emergency vet right now. Adder bites can cause rapid, progressive local swelling around the bite site.

What to do now

What to do right now

Call your vet or the nearest emergency vet.
Note what, how much and when.
Bring the packaging.
Keep your dog calm.
Remove what is left.

Don't

Do not make your dog vomit unless a vet tells you to.
Do not give any human medicine.

Why it can be dangerous

Adder bites can cause rapid, progressive local swelling around the bite site.^[1] All dogs in one study had variable severity of local swelling in the bite area, and 73 per cent had affected mental status.^[2] Vipera berus envenomation has a reported mortality of 3.5–4%.^[2]

Signs to watch for

Local swelling
Changes in mental status
Pain
Lethargy
Collapse
Vomiting
Bruising
Bleeding

If your pet is struggling to breathe, has collapsed, is having a seizure or can't stand up: go to the nearest vet now.

Not sure how serious it is?

OkPaw asks a few quick questions about your pet and tells you in 30 seconds whether it can wait. Free on Google Play for Android.

OkPaw is on Android now – an iPhone version is on its way.

Common questions

Can an adder bite be serious?

Vipera berus envenomation has a reported mortality of 3.5–4%.^[2]

Which signs can happen?

Local swelling and affected mental status were reported in dogs bitten by Vipera berus.^[2]

What should I do now?

Call your vet or the nearest emergency vet right now.

Sources

How this page was made: written with the help of AI from the sources below, then checked claim by claim against those sources. Urgency levels follow OkPaw’s fixed safety rules. It is guidance, not a diagnosis. How we write our pages