When it comes to purebred dog breeds, there are no better guard dogs than the following. They all possess the same traits that make them great guard dogs. They are intelligent, alert, strong, muscular, and fearless. They will do anything to make sure that their family is safe and out of harm's way. If trained properly, not only are these dogs great guard dogs, but also very loving family dogs that will show affection to their owners. None of these dogs should be kept in an apartment and all of them need room to run and play. They also need regular exercise and an owner who is confident and able to handle their strength and energy.
5. Doberman Pinscher

The breed is well known as a highly intelligent, alert, and loyal companion dog. They can be easily trained and should show aggression only when a true threat is present. They need to be trained early to prevent any unwanted aggression from developing. They are good with kids and need to be socialized when puppies in order to be friendly with other dogs. The dog typically stands between 26 to 28 inches 27.5 being ideal (66 to 72 cm), the female is typically somewhere between 24 to 26 inches, 25.5 being ideal (61 to 68 cm). The dog generally weighs between 75 and 100 pounds (34 and 45 kg) and the female between 60 and 90 pounds (27 and 41 kg). Dobermans need an owner who can show leadership and have the ability to be calm and collected at all times. The modern Doberman Pinscher is an energetic and lively breed suitable for companionship and family life.
4. Rottweiler

The Rottweiler originated in Germany as a herding dog. It is a hardy and very intelligent breed. They are a medium to large breed. The Rottweiler stands 25-32 inches at the withers for males, 24-29 inches for females, and the average weight is 50 kg (110 pounds) for males and 42 kg (93 pounds) for females. They are eager to work and willing to please their owner. They need an owner who can provide leadership and proper socialization. Proper training is the key to avoiding dangerous behaviour and having an obedient dog. Generally, the Rottweiler is a calm and confident breed with plenty of courage. They are usually calm when inside the house but need regular exercise to stay in shape and not get obese.
3. Boerboel

The Boerboel is a large working molosser breed of dog from South Africa. The ideal height for male Boerboels is 66 cm at the withers, though it can vary between 64-70 cm (25-28 inches). The height for the females should be 61 cm, but can vary between 59 to 65 cm (23 to 26 inches). Their weight should be between 45 kg and 90 kg (100 to 200 lbs). They were bred with the purpose of guarding the homestead. As a result, they have very have strong territorial instincts and are not friendly with strangers. They need to be trained and socialized early in life. Also, they need to be slowly introduced to people they do not know if you want them to be friendly with them. The Boerboel is a dominant but intelligent breed, with a strong watchdog instinct. They are great with children and love to play.
2. Dogo Argentino

The Dogo Argentino (also known as the Argentinian Mastiff) is a large, white, muscular dog that was developed in Argentina for the purpose of big-game hunting, primarily cougar and boar. They are very athletic and protective of their territory. The minimum height for the male is 62 cm (24.3 inches) at the withers, for the female 60 cm (23.5 inches). Maximum height is 68.5 cm (27 inches). They will not hesitate to show aggression if an intruder shows up. They need to be socialized with other dogs early in life as they can show aggression to dogs who try to dominate them or dogs of the same sex. They are gentle with kids but need to be trained and taught early what they can and cannot do as they are strong-tempered. They are not recommended for first-time dog owners or anyone with little experience in handling larger dogs.
1. Cane Corso

The Cane Corso is an Italian breed of dog used mainly as a guard dog. It is of the large molosser type. It is well muscled and looks more athletic than most other mastiffs. Dogs stand from 60-68cm (23.6-26.7 inches) at the withers, with females in the lower region and males in the higher. Weight should be in keeping with the size and stature of these dogs, ranging from 40-50 kg (88-110lbs). They look powerful and move very graciously. They are intelligent, loyal and easy to train. The Cane Corso is an excellent watch and guard dog and very suspicious around strangers. Cane Corsos are good with children and any family members. They will fearlessly protect their territory. They need to be professionally trained and socialized as they need to know who is in control. They are usually calm in nature with a stable temperament. They should only show aggression toward intruders or when a real threat is present.