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What You Need to Know About the Risk of Adder Bites to Your Dog

Sophie Jackson is a dog lover and trainer living in the UK. She competes in agility and obedience with her four dogs.

The Adder (Vipera Berus)

The Adder (Vipera Berus)

Can An Adder Bite Kill a Dog?

When the summer begins to warm up, many of us start to wander further afield with our dogs to enjoy the pleasant weather. What many of us fail to realise is that we are not alone in appreciating the heat. Adders, the UK's only venomous snake, are drawn out of hiding by the warmth, basking in the sun before hunting for their supper.

Unfortunately, Adders and dogs are not a great mix, and on rare occasions, a pet will be bitten by one of these beautiful snakes. Knowing what to do if such a thing occurs is vital to ensuring your pet survives a bite. Equally, knowing how to avoid adders will minimise the risk of a bite occurring, enabling you and your dog to enjoy the summer without fearing a snake incident. Not to mention, you will help to allow these rare and sadly declining reptiles to continue to exist in peace.

Sandy dunes are one of the locations where you might find an adder

Sandy dunes are one of the locations where you might find an adder

The UK's Only Venomous Snake

Most Brits have never seen an adder in the wild. They are secretive, shy snakes, preferring to avoid humans and dogs.

These snakes vary in colour from silver-grey to reddish-brown and have a distinctive zig-zag pattern down their backs and red eyes. Adults can measure 60–80cm in length and weigh between 50–100g. They can live for fifteen years if they are lucky, but many are preyed upon by crows and buzzards and even eaten alive by rodents while in hibernation over winter.

Being very shy in nature, they do not like being disturbed and will abandon their habitat if they feel threatened. Habitat destruction is an increasing problem for these snakes, and as of 2019, research has shown that the species is in rapid decline and on the brink of extinction in the UK.

Adders are protected under the Wildlife and Countryside Act 1981, making it a criminal offence to kill, harm, sell or trade them. Despite this protection, unwitting interference by humans is rapidly removing safe environments for the snakes.

This species has far more to fear from us than we do from it, and as it becomes increasingly rare, the chances of a person ever encountering one diminish greatly.

A beautiful female adder, showing the distinctive zig-zag markings

A beautiful female adder, showing the distinctive zig-zag markings

Avoiding Adders: What You Need to Know

Though they are in decline, dog walkers do come across adders on occasion. Most of these encounters will be a fleeting glimpse of a snake as it hastily slithers away from dog and human—remember, they want to avoid encounters with you as much as you want to avoid encounters with them!

Problems occur when the snake can't get away and feels it has only one resort—to bite in self-defence. Understanding the species, where it likes to hang out and when it is most active, is a key way to avoid trouble and to allow the adder to continue to exist in peace.

Adders are found across mainland Britain but are particularly common in the south and south-west of England, Western Wales and Scotland. They like grasslands, sandy dunes, heaths, rocky hillsides, moorland and the edges of woodland. They seek out areas where they can remain hidden while they hunt, but can easily reach open areas to bask in the sunlight. They also need places where they can hibernate safely over winter. An adder will return to the same hibernation spot year after year, which is why habitat destruction can have such a devastating effect on the species.

Since these snakes can be found in a range of territories, most of which are popular walking spots, simply avoiding where they live can be close to impossible. Fortunately, there are other ways to keep out of their way.

They are mainly active between March and October when the temperatures are warmer. This does vary by region, with areas such as Cornwall, that have short winters, seeing adders still basking in November. The majority of bites to dogs occur between April and July, though the reason for this is not entirely clear.

According to the Cornwall Wildlife Trust, the important thing to consider when watching out for these snakes is the temperature. When they are warm, they are alert and speedy; they will quickly get out of the way of a dog or person, as they really don't want to interact with either of them.

Cold snakes are another matter. When cold, they are sluggish and dopey; this is when it can be caught unawares and is likely to bite. Cold adders come out of their underground nests to bask in the sun to warm themselves and this is the point they are most dangerous. A dog coming across a sleepy, basking adder may step on it or sniff it in curiosity and the adder will feel it has no choice but to bite to defend itself.

To avoid this, it is best to walk either before the day has warmed up or when it is much warmer. If the temperature is below 10C, it is too cold for an adder to stray from its nest. This is also true if it is heavily raining. In contrast, in temperatures over 17C, these snakes are nice and warm and don't need to bask. Hot snakes will have no problem avoiding dogs and keeping them out of your way.

The Cornwall Wildlife Trust advises dog walkers to go out either when the temperature is below 10C or above 17C (though they admit this is only a rough guide). They also suggest walking before 9 am or after 7 pm, as these snakes are usually more active between those times.

Walking after dark is another option to avoid adders. They like the sun and will be safely in their nests at night. Walking at night can also be a way of avoiding the heat of the day in the height of summer, but can mean very late walkies!

Unfortunately, even when taking precautions, adder bites can occur and knowing what to do if that happens is the key to ensuring our dogs, or ourselves, survive the incident.

Dogs are naturally curious, and sometimes put their noses where it shouldn't belong.

Dogs are naturally curious, and sometimes put their noses where it shouldn't belong.

Adder Bites and Associated Risks

As scary as the thought of your dog being bitten by an adder sounds, we have to keep the risks in perspective.

According to Dick White Referral Vets, there are about 100 adder bites on dogs reported each year. Considering the number of dogs being walked daily in the UK, that is not many bites. In fact, during the summer vets are far more likely to see dogs suffering from heatstroke, with sometimes fatal consequences, rather than adder bites.

Another important thing to remember is that 96–97% of dogs will survive a snake bite if they receive veterinary treatment. That means the vast majority of dogs who encounter one live to tell the tale. The unlucky 3% who do not are often those with underlying health issues, or whose injury is not recognised as an adder bite immediately.

A similar number of bites occur each year to people. This is often due to a person trying to pick up a snake, or placing their hand in a small hole or crevice to retrieve something. Most bites occur between June and August, with numbers peaking in July. There has not been a death from an adder bite to a person since 1975—that's over forty years.

Adders prefer the edges of woodland, where there is sunlight. Walking deeper among the trees may help avoid them.

Adders prefer the edges of woodland, where there is sunlight. Walking deeper among the trees may help avoid them.

How to Recognise an Adder Bite

Adder bites are painful and the shock of the incident is usually enough for a dog to react with a yelp, run away, and limp if a limb is bitten. If a dog reacts in this manner after running in long grass, then an owner should consider the possibility of a snake bite.

Dogs are commonly bitten on the face or limbs (faces because a dog has stuck its nose too close to a snake, limbs because it has trodden on the snake). The first thing to do is to examine the dog for puncture marks. If a dog is limping or holding up a limb, it is a good guess it has been bitten on the sore leg and this should be examined closely. If the dog is not limping, it may have been bitten on the face, especially if it rubs at its muzzle.

If you can't find a source for the injury and you have any concerns that your dog may have encountered this snake, it is best to head straight to a vet and have them examine your dog. The more prompt the medical treatment, the quicker your dog will recover.

On occasion, a dog may be bitten when the owner is unaware. In this instance, the site of the bite will swell up over the next couple of hours. The affected area will be painful and bleeding, and a puncture wound should become apparent. The dog may be lame, or showing signs of discomfort. As the venom spreads through the dog, they may develop a racing heartbeat, fever, lethargy, heavy panting, drooling, vomiting, and they will wobble as they walk. Again, immediate medical treatment should be sought, even if it is outside the usual opening hours of your vets.

Remember, adder bites are venomous, and this venom can cause problems beyond a sore leg or face. It can lead to convulsions, or even death. Never hesitate to have your dog checked by a vet even if you only suspect an adder bite.

Dogs running through long grass may stumble on an adder

Dogs running through long grass may stumble on an adder

First Aid for Adder Bites and Veterinary Treatment

The moment you realise your dog has been bitten by an adder, it is vital you act. First, keep the dog still and examine for puncture wounds. The venom spreads faster if the dog is active, so carrying your dog, if possible, is a way of preventing the poison from spreading through the circulatory system. Get your dog to a vet as swiftly as possible. If you can, phone ahead and advise your vet of what you suspect has happened, that will enable them to be prepared.

You can bathe the affected area in cold water to ease the swelling, but the most important thing is to keep the dog still and warm as you reach the vet.

Your vet will aim to support the dog's organs and minimise pain, and they will also treat for shock. Fluids are given via a drip, while steroids and antihistamines may be given to reduce the after-effects of the bite. In severe cases, anti-venom is given, however, the anti-venom can induce an allergic reaction and so is only administered if absolutely necessary. There is considerable debate as to how effective anti-venom is, especially as there is no canine version, so dogs receive the human anti-venom.

During treatment, dogs are kept quiet, possibly on cage rest, to prevent the venom from spreading through the circulatory system. Pain management is also given to help the dog be more comfortable.

In very rare cases, a dog will develop serious problems from a bite; these could include breathing problems, an abnormal heart rate, bleeding disorders or convulsions. These usually only happen when an adder bite has gone untreated for some time, or when the dog has remained active after a bite, helping the venom spread through the body. Most dogs will make a full recovery if given prompt veterinary treatment.

On average, dogs can recover from an adder bite in 5 days, though some can take up to 30. Much depends on the size of the dog, how quickly they received medical care and how much venom the snake put in them when it bit.

Adder bites can sound scary, and no one wants to have their dog bitten, but by taking precautions and knowing what to do in an emergency, this type of bite need not be the end of the world.

We have to remember snake bites are extremely rare and it is an unlucky dog that finds itself on the wrong end of a snake. Equally, the majority of dogs will survive an adder bite. We must not, therefore, spend all summer worrying about the possibility or not walking our dogs for fear of what might happen to them.

And, at the same time, it is important to remember that adders are only acting in self-defence, they would prefer to avoid your dog than bite him. They are in rapid decline and it is feared that in the next twenty years they will be limited to a handful of locations in the UK. Rather than being frightened of them, maybe we should feel sorry for them—after all, they have far more to fear from us, than we do from them.

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.

© 2019 Sophie Jackson


Sophie Jackson (author) from England on August 05, 2019:

You are welcome

Larry Slawson from North Carolina on July 30, 2019:

Scary! Definitely don't like snakes haha! Thank you for sharing!