Saint Bernard Dog was bred for rescue missions in mountain passes earlier. It is a huge dog, standing in from 27 to 35 inches at the withers. It can weigh anywhere between 73 to 117 kg. This is a very friendly and loyal breed.
The Mastiff is the second largest of all dog breeds, weighing between 68–110 kg and the standard height is 30 inches. Great Danes and Irish Wolfhounds are taller than the Mastiffs but they are much smaller in terms of mass. Mastiffs are a muscular breed and they are well known for their courage and dignity. Mastiffs are considered sharp guard dogs all around the world.
The Neapolitan Mastiff is 26 to 31 inches high and weighs around 74 kg. This breed makes for a great guard dog because of their protective instincts.
Weighing about 60 to 70 kg, the Newfoundland is good at water rescue operations. Newfoundland dogs are extremely loving, patient and gentle dogs that make for a great house pet. It has webbed feet which makes it an outstanding swimmer.
The Dogue de Bordeaux (also known as the French Mastiff) is an old French dog breed. French Mastiffs are powerful big imposing dogs. They have a fearless character and are ideal for security duties weighing in from 54 to 65 kg with a height of 23-30 inches.
The Great Dane is considered as the second tallest dog after Irish Wolfhounds. Danes can weigh anywhere between 54 to 90 kg and has a height of 30-34 inches. This breed is tolerant with children.
The Irish Wolfhound is an ancient breed that has been used for many centuries primarily for wolf hunting. They weigh around 40 to 69 kg and have a height of 28-35 inches. Irish Wolfhounds are patient, intelligent and generous breed. These dogs are somewhat clumsy and are not recommended for guard duties.
The Perro de Presa Canario is a large and powerful dog that originated in the Canary Island and was specifically developed for dog fighting and large game hunting. This breed has an average weight of around 36 to 59 kg and is 21 to 25 inches in height. Presa Canarios are wonderful security dogs but they are not suitable for the novice or first time dog owners due to their dominant natures. This breed requires socialization and a lot of obedience training.
The Pyrenean Mountain Dog is also recognized as Great Pyrenees. It is commonly used as a guardian to the livestock. It is a serious and well disciplined dog that is wary of strangers weighing in at around 50 to 54 kgs.
The kuvasz is a large and ancient dog breed of Hungarian origin. They have also been used as livestock guardian. This breed of dogs weighs around 45 to 52 kg and is about 28 to 30 inches. The kuvasz is believed to be an independent thinker and can be hard to train.