He and his wife were woken about 5am yesterday (Thursday) by a loud crash outside their home on Colville Rd, just on the northern outskirts of Dargaville.
When he got outside he realised it was a plant pot that the dog had knocked over as it was mauling a sheep that had managed to escape the devastation in the paddock.
"It had bailed the sheep up against the house and was having a go at her when it must have knocked the plant pot over. The sheep had managed to escape from the paddock and [the dog] must have followed her to have another go," Mr Suckling said.
When he went to look in the paddock between the house and State Highway 12 it contained two other sheep that were dead and two more that had been badly mauled.
Mr Suckling said he then caught sight of the dog heading towards his back paddock that contained two more ewes and their lambs.
"It was heading for them. The wife yelled at it and it took off [in another direction] so didn't get them. But I think it would have if we hadn't called out."
He said the dog was a large mastiff-type that was brown with black markings. He said it was "pretty big" judging by the 10cm-plus long footprints it left on the concrete outside his home.
"We don't want it to come back and get the rest so we'll be keeping a watch out [overnight last night] in case it does," Mr Suckling said.
He said some of his neighbours were aware of the dog as it had been wandering around looking for other stock to attack recently.
Mr Suckling has reported the attack to Kaipara District Council. Owners of dogs involved in a serious attack on stock can be prosecuted and dogs may be impounded and/or put down if they attack people or animals.
If a dog attacks any person, stock, poultry, domestic animal or protected wildlife the owner can be prosecuted and fined up to $3000 if convicted. On top of this, they are also liable for the costs of any damage that occurs.
An Animal Control officer, dog ranger or police constable can enter any premises to seize and impound a dog that is deemed to be threatening the safety of any person or animal.