Concerned animal lovers considered breaking a van window after a dog was locked in looking "exhausted and depressed" from 7am until lunchtime.
Vanessa Green said she was concerned for the welfare of the dog.
"It got worse and worse, everyone wanted to smash the windows."
An SPCA inspector found the owner was within their rights to leave the dog confined all day.
Auckland SPCA chief executive Andrea Midgen said the owner's actions were not illegal.
"What is illegal is if that dog is compromised. If its stressed and panting and is at risk of harm, that is what we can act upon under the Animal Welfare Act," she said.
A laser heat detector found the temperature inside the van were within acceptable guidelines.
The owner also left water out for the pup and there was a degree of ventilation.
But Ms Midgen said dogs should not be waiting all day in vehicles.
"The best thing we can do is educate people around what they should be doing and thats not leaving a dog in a car for more than a few minutes."
"The number of animal welfare calls we get is increasing which is sad on one hand, but its great people are taking the time and the care to be bothered."