I have successfully represented Claimants after taking Witness Statements from other neighbours in the neighbourhood. On one occasion I obtained a statement from an ex-postal delivery woman. Interestingly, her previous employers, Royal Mail, did not want her to assist but when she left Royal Mail she was willing to help.
Sometimes Claimants may feel hesitant about suing someone who is their neighbour. However, on many occasions the keeper of the dog will have insurance through their home contents or building insurance policy so that they will not have to personally pay. The compensation you receive will come from their insurers.