Death row dogs: Owners fight to keep pitbull-types alive
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.
Sonia Gomez, who own Precious, said she thought she had bought a Staffordshire cross.
"I thought she was going to be a small dog," she said. "As she started growing people said 'she's going to be a big dog' and they were right."
She said Precious was brilliant with children and had never attacked or been aggressive. However, the dog grew into a big and illegal dog.
"A whole bunch of police all rioted up came charging for my son - they wanted to arrest him and take the dog," she said.
But, Ms Gomez won a court case to keep Precious alive, and it has now been sterilised and tattooed, with an order for it to wear a muzzle.
Tina Delaney, who runs a high security pound in Newham, said owners have tried scaling its walls to recover seized dogs.
She said many pet owners have been shocked their mongrel pup grew into an illegal pitbull.
"They go online or to rescues and don't know they are pitbulls, when they are puppies you can't tell," she said.
"When the dog matures they say 'that looks like a pitbull'. A lot of people when we seize their dog say 'I really didn't know it was a pitbull'."
Dog behaviourist Dr Roger Mugford, who has helped to fight cases in courts to keep dogs alive, said it had cost taxpayers about £20,000 to bring one prosecution and to hold a dog in kennels for 10 months.
"As a society we just can't afford this law, it's costing millions," he said.
"Millions on police catching dogs not criminals and millions in kennels and heartache to the families concerned."
The Metropolitan Police declined to be interviewed. However, it did confirm it had spent £1.3m housing illegal dogs last year.
The government said the current law helped to keep people safe from dangerous breeds and that there were no plans for change.
See more on this on Inside Out on Monday 18 February on BBC1 at 19:30 GMT.