More than 2800 people reported being attacked by dogs in the past year in NSW, with two people killed and 222 hospitalised.

Nearly 5000 other animals were also mauled by dogs and reported to councils over the 12 months to September 2019.

The number of attacks is likely to be far higher than the data suggests because many cases are not reported, Sydney dog behaviour specialist Nathan Williams said.

The City of Sydney had the highest number of dog attacks reported in proportion to the area's canine population last year. Credit:Ben Rushton

Within the Sydney basin, the City of Sydney had the highest number of dog attacks reported in proportion to the area's canine population in the three months to September, with 20 people attacked in an area with 24,184 dogs, a rate of 8.3 attacks per 10,000 dogs.