Three men have been questioned by police after a greyhound was found shot in the head with its ears cut off but still alive on a mountainside.
Both the greyhound's ears had been cut off
The incident, called "barbaric" by the RSPCA, sparked a joint appeal by the charity and Greyhound Rescue Wales when it was discovered last week.
Its ears, probably tattooed, had been cut off to stop identification.
A spokeswoman for the RSPCA said three men had voluntarily attended a police station over the action.
The black and white animal was found "extremely distressed" by a member of the public out walking their dog on Sunday 2 May on mountainside between Fochriw and Bargoed in the Rhymney valley.
It had probably been shot with a nail gun. The dog was taken to a vet and put down.
A post-mortem showed severe brain damage and a metal shard in its cheek.
A film of evidence is to be submitted to the RSPCA's headquarters, a spokeswoman said.