How to keep your dog safe from adders

It’s summer and in some areas of Cornwall, such as heathland and the Towans, there are adders around which can give dogs a nasty bite.

Mark Nicholson from the Cornwall Wildlife Trust has the following advice on how to keep adders and dogs apart

Have you ever been told not to walk your dog in hot weather when adders are around? The flawed logic behind that advice could actually end up increasing your chances of an adder encounter. Here’s why…

Beware of cool adders

A hot adder is alert and fast. It will readily detect approaching footsteps and slither away from danger. A cool adder is dopey and sluggish. It can easily be caught off-guard and, unable to escape quickly, will be forced to defend itself.

So cool adders are the ones you really ought to avoid. Those who study reptiles have become expert in recognising the best times and conditions in which to find cool adders. By cool adders we mean those warm enough to have come out of their underground shelters but too cold to be very active. In that state they bask to soak up the sun’s warmth, giving the surveyor a good chance to spot them.

close up of meadow viper the most endangered snake in Europe ( Vipera ursinii rakosiensis )

Watch the temperature

Dog walkers should do the very opposite of reptile researchers. There is little point in looking for adders when the temperature is much below 10°C or much above 17°C. If it’s very cold, or dark, or raining heavily, the snakes will not venture out. If it’s hot, they will have little need to bask and they will be too quick to see.

There are no guarantees, but if you stick to walking when it’s colder than 10°C or warmer than 17°C, and ideally allow for an extra margin of error on those figures, you will be a lot less likely to meet an adder.

Where are we likely to come across adders?

The classic adder habitats are heathlands, dune grasslands and other natural-looking grassy areas such as the towans (sand dunes) backing beaches such as Gwithian and Perranporth. You may have walked your dog amongst an adder population without even knowing it, as Cornwall is something of a stronghold for this declining and protected species.

Woman hiking on Bodmin Moor in Cornwall with dog.

Shift with the seasons and the weather

The time of day when reptile lovers are out looking for adders in that 10°C to 17°C window of opportunity varies with the weather and the season.The reptiles do hibernate, but in Cornwall our winter is short. You might well find adders basking in October, November, March and occasionally in even colder months. In spring and autumn, adder spotters typically search between about 9 and 11 in the morning and 4 and 7 in the afternoon to give them the best chance of finding an adder basking. That means you are relatively ‘safe’ walking before 9 am or after 7 pm – unless the weather is unusually warm for the season, in which case you need to go earlier in the morning or later in the evening.

In summer you have to get up very early in the morning if you want to walk before the adders wake. If the weather stays warm, they may still be moving around and basking well into the evening. The safest option, other than walking somewhere else, might be to go for a walk when it’s hot.

There are other complicating factors which make it impossible to give a precise definition of what is a bad time to walk your dog (or a good time to look for reptiles). For example, overcast weather with hazy sunshine filtering through the clouds can bring adders out basking at any time of day. Sunny periods between showers have a similar effect.

How serious is an adder bite?

To put things into perspective, many people in Britain have been bitten by adders – often because they pick them up – but the last death was in 1975. That’s over 40 years ago. Figures for dog casualties are hard to come by, but it does seem that most survive the experience – albeit with major illness and injury in some cases.

In the event of a bite, get to the hospital or vet, respectively, as quickly as possible but don’t panic. Try to slow down the spread of the venom by preventing running, over-excitement or movement of the affected area. Ideally, children and dogs should be carried.

To summarise

You can minimise the risk of stumbling upon a dozy, defensive adder by walking in areas where they are most likely to be found when it’s very cold, very hot or raining heavily. You can also walk in the dark, of course, as basking requires at least some sunlight. 

However much some people are afraid of adders, they have much more to fear from us and they will abandon an area if they are disturbed too much. Staying away – or keeping your dog on a lead – at the times when they are most vulnerable is good for your dog’s safety and for wildlife conservation.

Click here to find out more about the Cornwall Wildlife Trust