"We are hoping it was an isolated incident," he said. "It happens. Dogs are prey animals. Cats run, dogs will chase them."
He said a dog that killed a cat would probably not attack a person but it was a concern when any animal was killed.
"It's a concern that dog owners are not being responsible. If you see dogs roaming contact us."
Legally dogs are not allowed off their property without being on a leash, at any time of the day.
Mr Coutts said if residents were able to catch and tie up a roaming dog, an animal control officer would come out day or night.
"We can also supply dog traps, we do it all the time. We have half a dozen of them and are continually moving them from one property to the other."
He said although cats were allowed to roam wherever they liked, owners should consider keeping them inside at night.
"Wherever there's roaming dogs around Rotorua, there's a concern for cat owners."
A Kinder St resident told the Rotorua Daily Post her neighbour, the dead cat's owner, was distraught at its death.
She said she had heard of another cat being attacked in the area about a month ago, which luckily survived.
"People need to report these things. Too many people think it's a one off [and don't bother], that's wrong," she said. "Ring the council and keep your cats inside."To report a roaming dog, call Animal Control on (07) 348 4199.