Animals are suffering or dying because SPCA staff cannot reach them fast enough in Auckland traffic, prompting the organisation to build a new centre in Hobsonville.
Auckland SPCA acting chief executive Andrea Midgen said the animal rescue service has just one building in Mangere, which covers an area from Mangawhai Heads to Port Waikato.
It could take staff two hours to reach animals that need treating, she said.
"It's getting more and more problematic to rescue animals - some have died because of it."
Ms Midgen said volunteer foster carers, who look after puppies and kittens, also struggled to drive out for vet appointments.
"Typically, they'll take care of an animal for a few weeks, but if that animal needs treatment during that time, they have to come back and forth and it becomes a nightmare."
The SPCA will build on a new site at Hobsonville to reach north and west Auckland faster.
"It will be more of a satellite site - we're going to have an SPCA facility there and a base for our inspectorate to cover than north of Auckland area."
There would also be a doggy-daycare to help bring in revenue for the organisation.
The new site would be near a primary school and day care, making it easy for those who want to drop pets off for care to do so during the school run, she said.
Ms Midgen said SPCA hoped to fundraise $2 million to hit its $6 million goal to build and maintain the new site.
"People love animals and don't like to see them neglected or hurt, so we're hoping everyone will open up their hearts and wallets to help them out."
She said the SPCA would start earthworks in October, with a view to open in a year from then.