The only venomous snake native to the UK is the European adder and while adder bites in dogs are rare, it is between April and July that they are seen most often so is something to be aware of when enjoying the sunshine with your dogs. Adders are more active in the afternoons, so bites are more commonly seen at this time. They generally only bite in self defence but can be easily disturbed by a curious dog exploring on their walk.
Unless you have actually seen your dog get bitten, these are some symptoms to look out for. There may be pain and swelling around the bite and you may also be able to see two puncture wounds as well as bleeding in some cases. Dogs may appear lethargic, nervous, show signs of being in pain or exhibit lameness.
It is important to get your dog to the nearest vets as soon as possible (it is also useful to ring them first so that they are aware of what has happened and how soon you will be there), although with treatment, most dogs recover fully. If you can, carry your dog rather than let them walk, as this can lead to the venom spreading further in the body. Bathe the bite in cold water to help bring the swelling down and try to keep them calm on the way to the vets. With treatment most dogs make a full recovery.