A 'dangerous' dog seized by police was returned to his owners five weeks later having contracted a deadly disease.
Spike, an 18-month-old Staffordshire bull terrier, was taken by officers under the Dangerous Dogs Act, believing him to be an illegal breed.
After spending five weeks in a dog pound in West Drayton, tests confirmed Spike was not a banned breed and he was allowed home.
But the once lively and healthy dog was thin and had little energy and his owner, Maureen Baverstock, said she was shocked to see him in such a poorly state.
The retired 55-year-old, who lives in Stokesley Street, East Acton, said: "When my son went to collect Spike, he was in a terrible state; he could barely stand up and he had ulcers between his toes.
"We took him to the RSPCA and they told us he had parvovirus, a killer disease which breaks down the intestine wall and allows bacteria to pass into the blood stream. It is highly unlikely he will survive.
"We didn't have a problem with the police taking Spike as we knew he wasn't a pit bull, and they said he would receive the best of care at the pound.
"But what I do object to is the treatment of our dog in their care and I want an explanation as to why Spike was in such a terrible state.
"Spike picked up the disease while he was there and he was not the only dog in the pound. Something needs to be done to prevent the disease spreading to the other animals."
A Metropolitan police spokeswoman said the care and welfare of dogs seized was important to them and that measures were being taken to stop the virus spreading.
She added: "All dogs received into the care of the MPS are examined by a veterinary surgeon within 48 hours of arrival and vaccinated.
"The kennel has experienced staff and any concerns about a dog's welfare can be dealt with at the earliest opportunity.
"The owner of the dog has been contacted to reassure her that the kennels are of the highest standards and action will be taken following the possibility of canine parvovirus being present."