Great Lakes Council’s manager of waste, health and regulatory services John Cavanagh said rangers were concerned about the increase in public dog attacks and warned serious injury was imminent unless owners became more responsible.

‘‘Keep your dog locked up or on a leash when you are out and about, especially if your dog is known to be aggressive,’’ Mr Cavanagh said.

Mr Cavanagh said children, adults and other pets had been moderately injured in dog attacks since the beginning of the year.

In February, rangers issued 11 fines for offences relating to irresponsible dog ownership and 37 cautions.

‘‘The rangers issued 37 cautions without fines in February, only resorting to fines when owners continued to do the wrong thing,’’ Mr Cavanagh said.

NSW law requires dog owners to have control over their pet at all times in public places, whether at on or off-leash areas.

‘‘The laws are there for valid reasons, to keep children and others in our community safe, to maintain clean and healthy suburban areas and waterways and to prevent roaming dogs from pestering people,’’ Mr Cavanagh said.