People who own vicious dogs such as pit bulls have significantly more criminal convictions - including crimes against children - than owners of licensed, gentler dogs such as beagles, American researchers report.

A study of 355 dog owners in Ohio showed that every owner of a high-risk breed known for aggression had at least one brush with the law, from traffic citations to serious criminal convictions.

And 30 per cent of people who owned an aggressive breed of dog and who also had been cited at least once for failure to register it had at least five criminal convictions or traffic citations.