There was an aggressive dog on a footpath, it was tethered but my children were too frightened to walk past – is this allowed?

Under the law dogs are not considered dangerous animals but they can act in dangerous ways and display dangerous characteristics. If you feel that a dog is acting in an intimidating way that may dissuade you or other from using the right of way you should report to the highway authority. If a dog attacks you it should be reported to the police and the highway authority.