That amount is the same number of cats taken in for the whole of last year.
The demands on staff time and other resources are preventing staff from being able to carry out the SPCA's other animal welfare work, says Ms Shields.
"That is what SPCA is for, we're an animal welfare society, not a home for pet cats.
"I've fought against this, I've resisted coming out and saying no, we won't take any more cats.
"When they are brought in, by law we have to keep them a certain time, and if we can't rehome them we have to euthanise them. It's heartbreaking."
Most cats brought in are thought to be strays by the good-hearted people finding them, but are often just temporarily away from their permanent homes, Ms Shields says.
There is a strong possibility any well-fed, friendly moggie that turns up on the doorstep and hangs around for a short while is not a real stray - as in homeless, dumped or wild, and unwanted.
"If the cat is still hanging around after seven to 10 days then of course we'll take it, but we want the community to take responsibility for their cats, too."
The visiting cat is likely to eventually wend its way back to its real home, so wait a week before deciding it's a genuine stray rather than just an opportunist, Ms Shield says.
The SPCA is offering to provide a cat collar with a tab saying "If this cat is yours, phone xxx" to people who phone them about a friendly, hanging-around moggie.
When the cat slinks back to its real home, the owner can call the "finder's" number and affirm it is not a stray.
It might just help stem the flood.
The SPCA is desperate to free up its cattery and funds for emergency cases and animals that genuinely need rehoming.
While the Whangarei SPCA centre has a state-of-art facility for cats, "the dog kennel is disgusting, it's wet, cold, we can't keep the birds out, the court case dogs we house here have an inadequate exercise yard".
"That's a priority we need to put our money into."
To proactively reduce the number of unwanted cats, the SPCA desexes and microchips for its own data base all animals it rehomes.
NZ Veterinary Association (NZVA) has started a campaign calling for nationwide, local-government enforced legislation to promote responsible cat ownership and improve the welfare of all cats.
That would include microchipping and national registration; vaccination and parasite control; desexing; and management of cats in communities and areas where there is vulnerable native wildlife.
