A Mastiff off its lead in Clissold Park mauled and shook a Whippet, which underwent £8,000 emergency treatment following the traumatic attack, but died a day later.

Police are now appealing for information to trace the owner of the Mastiff, who left the park in Stoke Newington on Wednesday May 28 at around 10.30am with the dog which was covered in blood.

The Whippet’s owner, a 66-year-old man, had been walking his four dogs near the pond, when the grey-blue Mastiff ran towards them.

The large dog took the eight-year-old Whippet in its jaws and began to vigorously shake it, only dropping it when his owner approached.

She is described as a white female, approximately 5ft 7ins and aged 35 to 40ys, with blond hair tied in a pony tail.

The Whippet underwent veterinary emergency treatment, costing over £8,000, but died around a day later.

PC Matt Stringer who is investigating, said: “Although the victim was not physically harmed, this experience has been deeply traumatic for him and has been a cause for huge concern among other dog walkers in the area.

“It is all owners’ responsibility to ensure that they keep their dog under control to prevent this type of attack on other animals and potentially people too.”

He urged anyone with information about the owner or the incident to call police on 020 8721 2031 or, to remain anonymous, call Crimestoppers on 0800 555 111.