Amanda Quinn's cat, Gingy, died of a single slug-gun wound.
The Maunu woman had found the family's pet "really ill" on her back doorstep after farewelling a family member.
"He walked up, then collapsed. The gunshot hit below his ribcage and, since he died, I've asked all my neighbours about who may have done this," she said.
Gingy was shot on February 28 and, initially, Ms Quinn didn't go to police.
However, after learning of other cases highlighted in the Advocate, she wanted people to know what had happened so the culprit could be caught.
"I just hope that person is found. This sort of behaviour leads to problems when they (culprits) grow older," she said.
Police want to hear if other people have had pets shot, as concern grows that people may get hurt.
Whangarei police Sergeant Daniel Cleaver said: "Once the slug leaves the barrel, there's no control where it's heading and there's always the risk that someone could be inadvertently hit."
"Just because they are animals, pet owners think it's not worth reporting but, at the end of the day, firearms have been used and we'd like to know about it."
Several pet owners have contacted the Advocate since it was reported this week that Maunu resident Natasha Still's cat Fred had a leg amputated after being shot with a slug gun.
In Onerahi, Renee Faber's cat Marley was shot and had to be put down after a slug wedged in his spine.
"He came home one morning at 6am and was crying really loudly and, from there, he went downhill ... went off food, slept in strange places, vomited and wasn't urinating," she said.
The cat was put down two days later.
Ryan Cattin, a veterinarian at Mill Rd Veterinary Clinic, said he had treated two cats that had been shot in the past month.
"In general, we do not see very many shootings, although I suspect they are more common than we think, as I am sure a number of them never make it to the vet," he said.