Hundreds of dog owners in London say the law on pitbull-type dogs is not being applied properly, meaning their pets are being taken away and killed.The 1991 Dangerous Dogs Act outlaws pitbull-type breeds and last year, the Metropolitan Police seized nearly 800.
Some dog owners have said they did not realise their mongrel pup would grow into an illegal pitbull, as they are hard to identify as puppies.
The government said the law helped to protect the public.
Good behaviour and temperament do not stop seizures, instead officers decide if a dog has "too much pitbull" in it, using a set of physical measurements based on American fighting dogs.
'Heartache to families'
Battersea Cats and Dogs home says 92% of illegal dogs it is forced to hand to police for destruction would have made good pets.