Vets in Oswestry had to put the dog to sleep to end her suffering and now the RSPCA is appealing for help in tracing the person who left her to die.
The emaciated dog was found when an off-duty police officer came across her in an isolated spot above Glyn Ceiriog.
He took the friendly lurcher-cross to nearby Border Veterinary Centre in Oswestry where she was examined and staff discovered the ulcerated tumour on the side of the dog’s face which had grown into the upper jaw bone.
The tumour was so severe the vet decided the kindest thing to do was to put the dog to sleep to end her suffering.
Dave Martin, clinical director at the vets, said: “This was a nasty tumour and the dog must have been suffering like this for weeks if not months.