A convenience store in London Colney has been forced to close after a dog was killed when electrocuted while tethered to a metal pole outside the shop.

Two people who tried to rescue the stricken animal, a six-year-old Staffordshire Bull Terrier named Rhylie, had to seek medical treatment after receiving electric shocks.

The dog’s distraught owner Kate Callum said that last Wednesday (6) her daughter Carla, and grandson, five year old Malakai, took Rhylie for a walk when they stopped to shop at the London Colney mini-market on the village’s High Street.

Carla tied Rhylie to a metal post, used to hold the shop’s external shutters in place.

Kate added: “She got a bit of a shock, but assumed it was static, like you get from escalators. Carla went into the store and Rhylie suddenly started whining and then yelped.

“My dog was being electrocuted, and the collar got stuck in his mouth and every time Carla tried to pull the chain away, she was getting electric shocks. Carla yelled at the shop owner to turn the power off.

“My daughter was hysterical. She phoned my son Matthew for help. He got the collar off, but got a shock himself.”

Kate said although her “beautiful dog” died while tethered outside the shop her greater concern was that her grandson and children could “also be dead”.

Carla has sought medical help for swelling to her knee, pins and needles and chest pains, while Matthew has suffered pain in his shoulder.

Frantic with worry that a person would get electrocuted, she contacted Herts Police, Trading Standards officers and St Albans district council (SADC).

But when her husband told the shop about the pet’s death, he was apparently initially dismissed and told that Rhylie “must have had a fit”.

However, a vet who examined the dog’s corpse told Kate that Rhylie’s body showed signs of being electrocuted.

That prompted Kate to also phone UK Power Networks, distribution network operator, which later told her the shop front was effectively “live”.

A company spokewoman said investigations confirmed, “the shock was due to an internal electrical fault within the property, rather than the electricity network”.

SADC has served a prohibition notice on the shop’s owner, preventing the store from being open to the public.

A council spokesman said it would remain closed until the owner has given SADC a “full electrical safety inspection” report.

The mini-market could not be reached for comment.