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14
Jul
Our story about Elsa the cocker spaniel being bitten by an adder at Thruscross Reservoir surprised many readers and caused no small amount of consternation among local dog-owners.
Many wanted to know how likely an adder was to bite their dog, and some were also worried for their own safety.
So, just how common are adders in our district, and what do you need to know about them?
The only venomous snake indigenous to Britain, adders are actually more common in our area than many people think, a long-running snake survey suggests.
Thruscross Reservoir, where Elsa was bitten.
Make the Adder Count, which was started in 2005, is a survey of adder populations coordinated by Amphibian and Reptile Groups of the UK (ARG UK), and is updated with observations from volunteers around the country who count basking snakes after their emergence from hibernation.
Although adders are absent across most of our district, there does appear to be something of a hotspot in the Washburn Valley, with 90 records from the last two years, including 20 sightings around Scar House Reservoir and Ramsgill and 56 near Blubberhouses and Thruscross Reservoir, where Elsa was bitten.
That’s not to say that the Washburn Valley is a no-go area – far from it. According to vet Jonathan Mills of Forest House Veterinary Surgery in Knaresborough, where Elsa was treated with anti-venom, snake-bites are very rare. He said:
Over the last 30 years, I only remember one other instance, and that was when a dog belonging to one of our nurses was bitten on the leg at Swinsty Reservoir [also in the Washburn Valley]. It survived.
The adders tend to be nearer the top of the dale, in the forested and moorland areas, rather than on the cultivated farmland lower down.
One reason for the rarity of adder bites is the declining population of the species. Their range is huge, stretching from the Arctic Circle to Greece, and Britain to North Korea, so their international conservation status is “of least concern”. But in Britain, their status has been raised to “threatened”.
Chris Monk, chair of ARG UK, told the Stray Ferret:
In large parts of England, they’ve disappeared since the 1980s, due to loss of habitat, habitat fragmentation and persecution.
If you look through the historical records, it’s a wonder any have survived at all. In parts of the Pennines, where there were grouse moors, adders were seen as vermin. And there was one man in the New Forest, called Brusher Mills, who caught as many 30,000 snakes of different species and sent them to London Zoo to feed to animals that eat them as prey.
Typical adder habitat on moorland.
Nowadays, Mr Mills would undoubtedly end up behind bars, as it is illegal in the UK to kill, injure, harm or sell adders under the Wildlife and Countryside Act 1981.
The fact that that adders have survived, albeit in reduced numbers, may be due in part to the fact that they avoid disturbance and tend to live anywhere dry and frost-free, which often means relatively inaccessible places, such as rabbit burrows, underneath tree roots and in dry-stone walls.
Their mating season is in April and May, and they give birth to up to a dozen live young in August.
They mostly eat small mammals, such as voles and mice, but they’ll also eat frogs, toads and the chicks of ground-nesting birds.
Males are often grey with black zigzags on their backs. Females are usually brown with dark brown zigzags on their backs. They typically range from 60 to 80cm (2ft to 2ft 8in) in length.
An adder in long grass.
But even in the absence of humans, they can be vulnerable as they bask out in the open, warming up in the sun, and can get picked off by buzzards, which will come back time and again once they find a good basking spot.
Yet despite their relative rarity, they can pose a danger, especially in July and August, when incidents peak.
According to the Amphibian and Reptile Conservation Trust, between 50 and 100 people are bitten each year in the UK, and in the majority of cases, the effects are unpleasant but easily treatable. In fact, only 14 people are known to have died from adder bites since 1876, and the last one was in 1975.
However, there are also around 100 reports each year of adder bites to dogs, and they can be more dangerous, causing death in about 5% of cases.
Vet Jonathan Mills said:
The immediate effect is two puncture wounds, and a lot of pain. But then the venom causes all sorts of unpleasant effects, such as damage to tissue, inflammation, neurological problems.
The toxin spreads through the blood, so although the highest concentration is at the site of the bite, it affects organs all around the body.
It affects different animals in different ways, so you have to treat them accordingly.
In cases where a dog dies, they could go into organ failure or shock. More commonly, if the toxin causes tissue to die, it may cause a defect that the animal can’t recover from.
If it’s bitten on the leg, you could amputate and give them a better chance of survival, but if they’re bitten on the body, it becomes more difficult.
Common symptoms include:
As always, the best remedy is prevention, and there are practical steps every dog owner can take to keep their pet safe.
Chris Monk said:
Adders are moving around more at this time of year, so dogs are more likely to come across them, and when they do, they’re most likely to get bitten on the nose or the front paws.
So take precautions. Keep your dog on a lead, especially in areas that provide a suitable habitat for snakes. And if your dog does get bitten, carry it to the vet’s as soon as possible.
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