A grandmother has told how a dog savaged her own pet in front of her 11-month-old grandson.

A large bull mastiff dog called Tiger, standing guard at a taxi office in Thornton Road, broke free from its collar and launched a “horrifying” attack on Christine Ibberson’s alsatian, Jasmine. Mrs Ibberson, of Allerton, Bradford, had been walking down Thornton Road with baby Alfie when the attack happened.

“The first thing I knew it had grabbed my dog while Alfie was in the pram,” she said. “I was trying to separate them. I couldn’t, so I let go of the lead and it just clamped onto my dog – nothing could shake it off.

“Alfie was crying because I was screaming. It was horrific.”

Lorraine Barton, a mental health care worker from Queensbury, saw the attack while driving to work.

She said: “I got a can of de-icer and went to help. Other people were smacking the dog with chains and drain pipes and I was spraying it in the face but we couldn’t get it off for about half an hour.”

Mrs Ibberson suffered deep puncture wounds in her left hand and was taken to hospital for treatment.

A passer-by took nine-year-old Jasmine to the Gatehouse veterinary surgery in Allerton Road, where she was recovering yesterday.

Police say they cannot prosecute as the dog had been chained up and was not listed under the Dangerous Dogs Act. The dog’s owner, taxi driver Mabz Hussain, said Tiger had broken free from his new collar.

Tiger has now been removed from the taxi firm’s premises and Mr Hussain has agreed to pay Mrs Ibberson’s veterinary bills.

Mr Hussain said: “I would never have let it happen but I was away from the office at the time, though the dog was being supervised.”