The six were found in streets around Domain Park in Hamilton. No others have been found, despite extensive searches.
Hamilton City Council spokeswoman Fiona Sutton said the pups would be prepared for adoption.
Sutton said there had been an increased number of unwanted puppies in the past month and she urged owners to desex their pets.
Also this week in the deeper - and colder - south, four mastiff-cross puppies were dumped in Oamaru. They were due to be euthanased as there was no room at the animal shelter or SPCA but shelter staff used social media to seek homes. The puppies were vaccinated, wormed and went to new homes.
Vicki Whitaker from the Western Animal Shelter in Auckland said animal pens were overflowing.
"This is, unfortunately, a seasonal trend that we see when the weather starts to turn cold and wet and the realities of having to walk a dog two to three times a day becomes too much for some," she said.
• Do you have information the litter of blue heelers? Email: news@hos.co.nz
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