The female bull breed was brought into the PDSA Pet Hospital in Oldbury, Sandwell, on 29 March by a man who said the dog had been hit by a car but left before he gave his name.

The animal had deep knife wounds all over her head, body and legs as well as fractures and bruising, the RSPCA said.

This poor dog would have suffered a great deal,” the charity added.

RSPCA Inspector Boris Lasserre said: “The nature of the wounds show the horrific mutilation of the dog was not post-mortem. Clearly this savage and prolonged attack led to the dog’s eventual death.

The charity said they want to trace the man who brought in the dog as part of their investigation to work out what happened to the animal.

The man was black, about 20-30 years old and was wearing black trousers, a black jacket and black cap, Mr Lasserre said.

He carried the dog’s body wrapped in a blood-drenched sheet and a B&M shopping bag.

“We understand the man carried the dog into the clinic having arrived there on foot so we would be interested in hearing from anyone who was in the area at the time or from any drivers who have dashcam footage,” Mr Lasserre added.

We also appeal to anyone who may have heard a dog screaming in agony on the morning of the 29 March.