The RSPCA in Swansea says it is seeing an increase in the number of abandoned cats and kittens it's taking in.
Staff there described this year as the 'worst ever' for the problem and said they're struggling to cope.
The problem stems from cat owners being caught out when their un-neutered pets have litters.
Now the society is working with Cardiff University to try to establish why owners aren't taking preventative measures.
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