He said the thefts happened on more than one occasion every year and estimated there have been 26 occasions so far.
"I've largely given up grazing sheep as the thefts are most frustrating to me. There are plenty of people who'd know who did it but I guess you can't identify meat in a freezer.
"These things often happen on farms and farmers wouldn't notice it for several weeks or not notice it at all if they've got hundreds of animals," he said.
Dargaville police confirmed a report has been lodged but no arrests have been made to date.
Sheep belonging to other members of his close family have also been stolen or mauled in the past.
Just over three years ago, a large dog believed to be a large mastiff-type mauled to death two sheep and badly injured three more that belonged to Suckling's father Vern on the northern outskirts of Dargaville.
Vern Suckling and his wife were woken up by a loud crash outside their Colville Rd home and when he went to check outside, he realised the dog had knocked over a plant pot as it was mauling a sheep that had managed to escape.
READ MORE:
• Sheep mauled and killed by dog
• Dog impounded over sheep attacks
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. Owners are also liable for the costs of any damage that occurs.
An Animal Control officer, dog ranger or constable can enter any premises to seize and impound a dog deemed to be threatening the safety of any person or animal.