There was a large wild cat population in Wairarapa from when cats had been dumped in parks which then "bred like fury".
Ms Priest said some of the cats that came in were too sick or "too wild" so had to be put down. "Those that are friendly enough - it's policy we don't put down a well animal. Our job is to give them homes."
An anti-cat campaign by high-profile New Zealander Gareth Morgan and the economic climate had deterred potential cat owners from adopting a new pet, she said.
"They're going out, but it is slower than last year."
Kittens were available from the SPCA for $100, and came desexed and vaccinated.
Royal New Zealand SPCA national president Bob Kerridge said it was "kitten season" nationwide. Depending on the weather, the kitten season extended from December to March. "This year's a bit longer because of the weather." The kitten overload appeared to be nationwide, many SPCA holding facilities filled "to capacity".
Foster homes were an ideal solution to the furball explosion, as kittens could be cared for until they were old enough to be adopted out.
"That means that they don't have to be held at the centre."
Fostering could be hugely satisfying, Mr Kerridge said. "Many lives are saved because of foster homes."
However, adoption was the only permanent solution. "We urge people if they're thinking of a kitten to come to us."
Cats were held for as long as it took for them to be adopted, Mr Kerridge said. There was no set timeframe, although cats tended to take longer than kittens to be rehomed.
"Sometimes we do get elderly cats in that may have come from a deceased estate, and the older cats are a little bit more difficult to adopt."
Mr Morgan's Cats To Go website has drawn widespread outrage from feline fans after he suggested cat owners not replace their pets when they died.
He said local governments should require registration and microchipping of cats and to facilitate the eradication of unregistered felines to protect native birds.
The argument reached fever pitch when Mr Morgan offered to donate $5 to the SPCA for every homeless cat it put down.
Mr Kerridge replied: "Butt out of our lives, and don't deprive us of the beautiful relationship that a cat can provide, individually, and in our families."
APNZ