Napier mayor Richard McGrath has stood down his deputy mayor Sally Crown after she refused to resign and instead requested he undergo leadership training.

Nine and a-half months after his son was born, Mukzameel Mukhzar Ali killed the boy, using such force that he lacerated the baby’s liver and his large bowel in two locations.

Three police staff have left their jobs following investigations in relation to "misuse and inappropriate content".

"This is not a s*** owner, this is not s*** dogs. This is just a really, really horrible event."

A veterinary specialist says it was shocking to see another serious dog attack in Christchurch over the weekend, just days after a woman was mauled to death in Northland.