A ban of American bully XLs has led to dogs being abandoned and “killed en masse”, the founder of a pet rescue centre has said.
People who work to rehome dogs have told the BBC some pounds are killing up to eight strays a day.
The vast majority are understood to be bully XLs, which are being added to the list of banned dogs from 1 February.
The Department for Environment, Food and Rural Affairs (Defra) said it had taken action to protect the public.
XLs are variations of American bullies, which originated in the US in the 1980s.
They are being added to the list of banned dogs in England and Wales because of links to a number of fatal attacks, including most recently on a man in Walsall.
Days earlier, an 11-year-old girl, along with two men, were attacked by an American bully XL in Bordesley Green, Birmingham.
The BBC has spoken to dozens of dog experts, including charity workers, vets and wardens.
They claim that since the ban was announced in September, large numbers of dogs have been abandoned, exacerbating an acute shortage of kennel and rescue spaces.
Pounds holding unclaimed strays can ask for them to be put to sleep by a vet after seven days.
