SPCA Otago executive officer Sophie McSkimming said there were about 200 cats available for adoption, including 60 kittens coming from foster care.
The cats being dropped at the shelter were mainly females and pregnant or with kittens, Miss McSkimming said.
Many cats were being dumped by their owners, she said.
''People bring them to us, and say they found it, but it's really their own cat, with kittens. We get a lot of that.
''They don't want to deal with it, so it's easier to say they have found it in the back yard and bring them here.''
When a cat was brought in, it went into a special room for a week, during which time its owners could claim it.
Cats not claimed after seven days became SPCA property and were desexed and made ready for adoption.
The shelter was running close to capacity on cats, Miss McSkimming said.
''As soon as one goes, we have another to replace it.''
In an effort to ensure there was enough space for all the unwanted cats, the shelter had been adopting out female cats at half-price ($60) for the past month, which included vaccinations, microchip and desexing, she said.
The promotion would continue until there were fewer female cats coming in.
A cat could stay at the shelter until it found a home, Miss McSkimming said.
One cat called Nola had been at the shelter for 18 months after coming in as a kitten, she said.
''Those cats can be here forever but then someone goes 'Oh, I love her'.
''It just takes that one person.''
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