The owner of a rescue dog that bit a McDonald’s employee has been told the animal will be put down if it is seen outside without a muzzle.

Wally, a Lancashire Heeler, bit an employee of McDonald’s Hayle restaurant when she walked past it to the staff non-smoking area while it was tethered to railings. The bite ripped her trousers, covered her leg with blood and the dog maintained it grip when she tried to pull away.

At Truro Magistrates’ Court, Monika Williams, aged 55, of Sparnon Hill, Redruth, pleaded guilty to having a dog that was dangerously out of control on November 4, injuring Nicola Richardson.

Alison May, prosecuting, said Ms Richardson, aged 17, was walking past the dog when it sunk its teeth into her left leg. She tried to pull away but it was still hanging on. Williams ran out from the restaurant and offered to pay for the teenager’s trousers.

“Ms Richardson was shocked and crying and clutching her leg which was covered in blood,” said Ms May.

Williams gave the victim her contact details and said the dog was usually muzzled.

Ms Richardson was taken to hospital in Penzance for treatment. She was given antibiotic treatment, but had an unpleasant reaction to it, and had to stay away from college for a week. She had been left fearful of having any dog near her.

Ms May said there had been a similar biting incident with the same animal in July last year when the dog had been tied to railings.

Williams told the police she had intended taking the dog to the beach and so had not muzzled it that day, but then the weather changed and she went to the restaurant.

Since the incident she had gone to McDonald’s and taken chocolates and flowers for Ms Richardson.

Paul Simons, her solicitor, said: “Wally kicks off when he is tethered to railings and not in her company. She has had him for eight years and is genuinely remorseful about what happened.”

Williams was ordered to pay £150 compensation to Ms Richardson and £60 court costs.

The magistrates made a contingency destruction order calling for the dog to be muzzled whenever it left the house or it would be destroyed.