Should dog owners be worried about adders during the summer heatwave?

Dog owners are being urged to remain alert for adders while walking in the countryside this summer, but experts say there is no reason to panic or assume hot weather has caused a surge in Britain’s only venomous snake.

Adders are naturally more active during the warmer months, with most encounters and bites occurring between spring and early autumn.

However, online claims that a heatwave simply “brings out” more adders are misleading. As cold-blooded reptiles, adders rely on external warmth to regulate their body temperature and may bask in sunshine when conditions are suitable.

During extremely hot weather, however, they are likely to avoid the strongest midday heat and seek shelter in vegetation or other cooler places.

This means dogs could still encounter a concealed snake while investigating long grass, heather, gorse, brambles, stone walls or woodland edges.

The Amphibian and Reptile Conservation Trust says the majority of recorded adder bites occur between April and September, with a marked peak during July and August. This is thought to reflect both the snakes’ seasonal behaviour and the greater number of people and pets visiting the countryside.

Vets4Pets says bites involving dogs appear to be most common during the afternoon, when adders can be active.

Rachel Bean RVN is the UK's leading canine first aid tutor

But bites remain rare. Amphibian and Reptile Conservation estimates that around 100 suspected dog bites are reported annually to veterinary poison specialists, despite millions of visits to areas where adders live.

Adders are shy and will normally retreat when they sense people approaching. They do not hunt dogs or deliberately seek confrontation, with bites generally occurring when a snake feels threatened after being sniffed, pawed at, stepped on or disturbed.

Curious puppies and young dogs may be particularly likely to investigate one.

Canine first aid expert and veterinary nurse Rachel Bean said: “Dog owners should be aware of adders, but they should not be frightened of taking their pets into the countryside. Bites are rare and adders will normally try to escape rather than confront a dog.

“The most important thing is to know what to do if a bite is suspected. Keep your dog as calm and still as possible, carry them if you can and telephone the nearest vet immediately. Do not wait to see whether swelling or other symptoms develop, because prompt veterinary treatment gives a dog the best chance of making a full recovery.

“Do not apply an ice pack to the area or attempt to treat the bite yourself. Simple precautions, including keeping dogs close, preventing them from investigating long grass or dense undergrowth and making plenty of noise as you walk, can reduce the risk considerably. Snakes are sensitive to vibrations and will usually move away if they sense people approaching.”

Dog owners walking through known adder habitat are advised to keep pets on a lead, remain on established paths and discourage them from exploring dense vegetation.

Making plenty of noise while walking may also help alert snakes to the presence of people and dogs. Adders are sensitive to vibrations through the ground and will generally retreat if given the opportunity.

Adders are found across England, Scotland and Wales, although they are locally rare and declining in many areas. Their favoured habitats include heathland, moorland, peatland, coastal dunes and cliffs, chalk downland, rocky hillsides and woodland edges.

They can be recognised by the distinctive dark zigzag running down their back. Adults are generally around 50 to 60cm long, although some can reach approximately 70cm. They also have red eyes with vertical pupils and often carry a V or X-shaped marking on the head.

Bites most commonly occur on a dog’s face or legs. The first sign may be rapid swelling around the affected area, sometimes accompanied by one or more small puncture marks.

Other symptoms can include pain, bruising, bleeding, lameness, lethargy, fever, drooling, vomiting, an increased heart or breathing rate and an unsteady gait.

In severe cases, a dog may collapse, experience breathing difficulties, develop blood-clotting problems or suffer organ failure, tremors or convulsions.

Anyone who believes their dog may have been bitten should contact the nearest vet immediately and ring ahead to warn the practice they are coming.

Owners should not wait for symptoms to develop. The dog should be kept calm and carried where possible, because physical activity may help venom circulate through the body.

No ice or ice packs should be placed on the bite, and owners should not cut or otherwise interfere with the wound, apply a tourniquet or attempt to administer treatment themselves.

They should also never attempt to catch or kill the snake. A photograph may help identify it, but should only be taken from a safe distance and if doing so will not delay veterinary treatment.

Despite the potentially serious symptoms, most dogs recover with prompt veterinary care. Vets4Pets says between 96 and 97 per cent of treated cases survive, while Amphibian and Reptile Conservation cites a British study in which just under five per cent of bites were fatal.

Adders are protected under the Wildlife and Countryside Act 1981, making it an offence to deliberately kill or injure them.