Has my dog been bitten by an adder?

The European adder is the only venomous snake native to the UK. Adults are up to two feet long and have a black or brown zigzag pattern along their back and a V-shaped marking on the back of their head. They’re most commonly found on dry sandy heaths, sand dunes, rocky hillsides, moorland and woodland edges, particularly in the south and south-east of England. They tend to inject around 1ml of venom into their victim when they bite.

Urgent treatment may be needed if your dog has been bitten by an adder so please contact your vet as soon as possible for advice or, out of hours, your nearest Vets Now pet emergency clinic or Vets Now 24/7 hospital.

Symptoms & treatment

How common are adder bites in dogs?

Adders only bite in self-defence. Generally, bites occur when a snake is stepped on or disturbed by your dog.  Bites are more frequent in the spring when the snakes are just out of hibernation. However, cases are also seen throughout the summer as adders become more active when the weather improves. Sometimes they can be seen basking in the sun. It’s worth bearing in mind that wild snakes are protected by law in the UK and it’s an offence to intentionally injure or kill an adder.


How will I know my dog’s been bitten by an adder?

Adder bites typically result in swelling that’s dark in colour. Be aware that the swelling can become severe and, if the bite is around the face, it may result in breathing difficulties.  You may be able to see two small puncture wounds in the centre of the swelling.  Your dog will also show signs of pain and may appear nervous.  Other signs of an adder bite can include pale gums, bruising, drooling, vomiting, diarrhoea, dehydration, restlessness, drowsiness, and lethargy.

Eventually, if left untreated, dogs may collapse, have blood clotting problems, tremors or convulsions. Most bites occur on a dog’s legs or face.


What should I do if my dog is bitten by an adder?

Seek veterinary attention quickly if your dog is bitten.  Carry your dog — rather than allow him to walk — to try to reduce the spread of venom around his body.  Bathe the wound in cold water to help control the swelling and keep your dog quiet and warm as you transport him to the vet.

The vet is likely to treat your dog for shock and swelling and give him pain relief. Anti-venom will also be administered if it’s available. Most adder bite cases survive with appropriate treatment. One study into adder bites in dogs found fewer than one in 20 died as a result.

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