In New Zealand the Bullmastiff is classified as a Utility dog. The Bullmastiff is a large dog, ranging between 60.9 - 68.5 cm (24 - 27 inches) at the shoulder. They are a very powerful dog, weighing between 40.8 - 58.9 kilograms, but are also extremely gentle in nature.

In England, in the early 1900's, the Bullmastiff was developed by mixing the Old English Mastiff with the old fashioned British Bulldog. The intention was to create a dog capable of assisting gamekeepers in their efforts to prevent poaching. Rather than biting, the dog would knock down the poacher and pin him, allowing the night watchman to take him into custody.

Today the Bullmastiff is a fantastic watch dog and affectionate family companion. They have a very loving nature and are at their best when they can be a true part of the family. They are a very even tempered and laid back dog which gets along wonderfully with children and other animals. Of course, as with all dogs, especially those of a larger size, it is imperative that the Bullmastiff should have basic obedience training and be well socialised to enable him, or her, to fit well into the family and be a well adjusted member of society.