The RSPCA says it is being swamped with abandoned kittens at its branch in Swansea, with staff saying its the worst year ever.
Now the organisation is working with Cardiff University to find out why owners aren't getting their cats neutered.
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The world record attempt will raise money for the foundation set up in memory of the Olympic gold medallist, who died in May 2013.
In today's Newsweek, Carl talks about what the 'No' vote in the Scottish Referendum could mean for Wales and the impact of legal highs.
England manager talent spotting at Swansea City v Southampton at the Liberty Stadium