Animal welfare officers in Canterbury are still looking for a person who shot a bull terrier three times in the head.
A passer-by found the dog, still conscious, tied to a fence near the Waimakiriri River in West Melton, west of Christchurch.
The animal was taken to Society for the Prevention of Cruelty to Animals (SPCA) where it was put down because of the extent of the injuries.
"The person who did this probably thought they had killed it, but the dog was found awake, sitting up, and likely in terrible pain," SPCA Canterbury manager Geoff Sutton said.
It was not clear how long the dog had been left tied to the fence but if it had not been found its suffering could have gone on for days, he said.
"It's not an offence to kill an animal, but it's got to be killed humanely and not left in pain and suffering."
SPCA said today that it had received several calls from concerned members of the public but the dog's owner was still not known.
An autopsy would be carried out today.