A third of dog owners in the UK have been bitten or attacked by their pet dog, a new study has found.

Researchers showed that almost one in three (30 per cent) dog owners have been bitten or attacked by a dog with over half (51 per cent) knowing someone else who has.

The rise of the unruly dogs has been blamed on a lack of discipline when they were puppies when their owners did not be bothered to have them trained properly, the ‘Daily Mail’ reported.

A leading veterinary charity in the UK has warned that millions of dogs are more aggressive due to gaps in their pet knowledge.

A study of pet owners by the charity found that around 5.3 million dogs (some 61 per cent) never attended training classes within the first six months of life.

It said 1.3 million dogs across the UK are now displaying behavioural problems.

While in some cases dogs are deliberately trained to be aggressive, the report found that the primary cause of the anti-social behaviour is a lack of socialisation and basic obedience training when dogs are young.