The dogs were suspected of being banned Pitbulls after the attack on Jill Jones and her Cockapoo in Stocks Road on Sunday December 30.
The out-of-control dogs were swiftly tracked down and seized by police immediately after the attack.
Officers assessed them to determine their breed, but tests revealed that the dogs were not believed to be Pitbull.
But even if the legal status of the dogs is confirmed, they could still be destroyed if they are considered a danger to the public.
Police said the dogs will not be returned to their owners until a full investigation into the attack has been concluded.
Until then, the dogs are to be kept secured in police kennels.
According to a police spokesman, the investigation has been delayed because officers have been unable to interview the woman in charge of the dogs.
"We haven’t yet been able to interview the woman who was in charge of them, so enquiries are ongoing.
"The dogs will stay in kennels until the investigation is complete", said the spokesman.