"If you've got a pet you should be taking it to your local vet to be de-sexed," he said.
"The trouble is a lot of people can't afford that. The major barrier to de-sexing pets is cost.
"You should think about that before you get a pet though. Think about your income and lifestyle, and what it's going to cost you. It's a responsibility thing."
Meanwhile the Kaitaia visit followed an established routine, cats going under the knife in the mornings, dogs in the afternoons.
One or two feline patients arrived with the snuffles and were turned way however - as with people, any kind of lung congestion added to the risk of anaesthesia, Mr McKellow said - and a few didn't keep their appointments.
The shaving of a leg, administering the anaesthetic and emptying the bladder seemed to take almost as long as spaying itself for tom cats, and even the females were done and dusted within around seven minutes.
The cats went home in pillow cases, standard procedure to eliminate their chances of escaping somewhere between theatre and the owner's cage, their incisions neatly closed with dissolving stitches and with the assurance that they would running on all six cylinders again by day's end.