Dog owners are being warned to keep an eye on their pets after a series of adder attacks.

Vets have seen an increased number of dogs suffering from adder bites which cause swelling and can be fatal if left untreated.

On Monday Michelle Jones was walking her 19-month-old dog Lulu in Honeysuckle Lane on the South Downs near Worthing when her pet was bitten by an adder.

She rushed Lulu to Grove Lodge Veterinary Surgery in Worthing. The dog was kept in overnight but after coming home became ill again and had to be taken back to the vet today.

Adders are often found on the South Downs or in heathland areas or woodland edges. Generally they will avoid people and animals but young inquisitive dogs occasionally get bitten if they surprise the snakes.

Adders are the only venomous snake in Britain and are identified by a brown or black zigzag pattern on their back with a V-shaped marking on the head. They are protected under the Wildlife and Countryside Act from being killed, injured or sold.