2009 saw a big increase in the numbers of stray dogs recorded as being picked up in the UK. Tom Heap discovers that many of the unwanted dogs in pounds and rescues are Staffordshire bull terrier types - and asks why so many of them are being let go and destroyed. Has the fashion for aggressive looking 'status' dogs contributed to the numbers of abandoned pets the authorities are now having to deal with? Panorama has gained access to one of the most famous animal rescues in the world, Battersea Dogs Home, and reveals the shocking truth of the numbers of dogs it is having to put to sleep.