1. Pit Bull

This type of dog has been known to come second to none in dog fights. When people hear the word “Pit Bull”, they typically associate it with dogfighting and extremely aggressive behavior. Rightfully so, considering all that has been in the news regarding this extremely muscular and tough-looking breed. The Pit Bulls ancestors, the Bulldog, were used for dog fighting and bull baiting a very long time ago. It’s unfortunate that some illegal dog fighting rings still operate.

It’s equally as unfortunate that some of the time, this breed gets into the hands of an irresponsible owner who uses these dogs to fight for a profit. Most times this breed is not neutered or spayed and may be tied outside or left to roam free. It’s the perfect mixture for creating an aggressive dog. Many were bred to be aggressive and this pattern will most likely continue.

2. Rottweiler

Did you know that the Rottweiler was responsible for half of all dog-related deaths in the United States between the years of 1993-1996? It goes without saying though that they are well known for being extremely loyal, friendly, and family safe dogs. In fact, a children’s book was published called “Good Dog Carl” who is portrayed as a friendly dog.

However, when they get into the wrong hands these dogs, most times weighing well over 100 pounds, can be seriously dangerous. In some places, this breed is on a list of dangerous dogs that aren’t allowed. Rottweiler’s have quite a large head with a wide jaw that can have a crushing force when it bites. These dogs can be just as dangerous as the loaded guns some keep in their homes.

3. Doberman

The Doberman was first introduced to the United Kingdom and America from Germany in the early 1900s. They somewhat resemble the Rottweiler and share a similar reputation when it comes to poor training. To an inexperienced trainer, things can turn bad fairly quickly.

The Doberman was first introduced to the United Kingdom and America from Germany in the early 1900s. They somewhat resemble the Rottweiler and share a similar reputation when it comes to poor training. To an inexperienced trainer, things can turn bad fairly quickly.

4. German Shepherd

The Doberman was first introduced to the United Kingdom and America from Germany in the early 1900s. They somewhat resemble the Rottweiler and share a similar reputation when it comes to poor training. To an inexperienced trainer, things can turn bad fairly quickly.

Because these dogs have been labeled dangerous, some areas may require that you have some type of enclosure that is strong enough to hold the dog back and to keep him or her from escaping. In addition, some states may require liability insurance.

5. Great Dane

Great Dane’s are notorious for being known as the ‘Gentle Giant’. However, if they aren’t properly trained and socialized frequently as puppies, things can go downhill fast. They are one of the largest dog breeds out there, and because of their size, they have the potential to be extremely dangerous.

A Dane that is mistreated by his or her owner has the potential to turn on them and cause a great deal of damage. An adult can easily weigh up to 200 pounds which can prove to be detrimental if not trained and treated properly.

6. Fila Brasileiro

Also known as the Brazilian Mastiff, this dog is known to be a very large and powerful dog. They weigh up to 170 pounds. Initially, they were bred to be a hunting dog that was trained to restrain but not kill the prey. Going back in history, this breed was used to return fugitive slaves unharmed to their owners. They have become a fairly popular guard dog over the years.

The Fila is a bit different from other mastiff dogs due to its temperament and ability to be very aggressive. At this time, the Fila is banned in the United Kingdom, Norway, Israel, and Denmark. If not properly trained, they can become extremely aggressive towards strangers. All in all, their size in conjunction with their strength and aggressive nature, this breed makes the list for one of the most dangerous dogs.

7. Boxers

The Boxer is from Germany and is a very strong breed. They can weigh anywhere between 50-70lbs. They are known to be energetic and playful which labeled them as being hard to train. By nature, this breed is not typically violent or aggressive.

If you saw them walking on the street, they do appear to unfriendly even though that is most likely not the case. However, don’t mistake this typically friendly dog as never being aggressive because they can attack at any time under certain circumstances. A death by a Boxer was caused back in 2015.

8. Bull Terrier

You may recognize this breed from the Target commercials. Pound-for-pound muscle this dog is extremely strong. Like many terriers, Bull Terriers have an extremely strong prey drive. They may be less dangerous to humans, but the smaller pets in your home may not be as safe.

If you have a home filled with smaller animals such as cats, you might want to think twice before bringing a Bull Terrier into your home.

9. Dalmatian

This iconic fire-house dog actually has a reason for its poor trainability. Many of these dogs are born deaf which can result in them becoming rambunctious and quite dangerous.

Most people are unaware of this problem, and it’s difficult to train a dog that is unable to hear. This can become frustrating to their owner and can lead to the dogs being neglected, poorly socialized and trained which can cause them to be extremely dangerous to people.

10. Malamute

This breed looks very similar to the Siberian Huskey. However, they are larger and are typically more dangerous by nature. They weigh between 75-100 pounds and are 23-25 inches in height.

Originally, they were bred for sled use. These dogs need proper exercise and a lot of room to roam free. If not, they are known to destroy their owner’s property. They don’t get along well with other dogs, even if the other dog is the same breed. Fights often will often occur with these dogs. Also, these dogs can become very possessive of their food and can become extremely aggressive if you try to get close to their meal.

11. Husky

Similar to the Malamute, Huskies were used as sled dogs which means they have a lot of energy, strength, and muscle bred into them. They are a medium-sized breed that is meant for environments with extremely low temperatures. They are meant to be working dogs which makes it hard to domesticate them.

Back in 2009, 6% of fatal dog attacks were from Huskies. It’s not recommended that you leave small children or smaller animals alone with this breed as they are known to become vicious and attack.

12. Alaskan Malamute

Though The Alaskan Malamute and the Malamute our different breeds all together there are many similarities between the two. They are both very active and strong dogs.

When the Alaskan Malamute training isn’t sufficient, or it doesn’t get enough exercise, they become bored and they can get aggressive.

13. Caucasian Ovcharka

This breed is very smart and a strong-willed guardian dog. They are known to be gentle with their owners, but they tend to be very wary of dogs and other people they don’t know. They are very quick and are known to protect their family if they feel they are threatened.

They are very alert dogs so if there are noises or changes in their surroundings be prepared for barks and growling. It’s important that these dogs have the proper socialization and training otherwise it will be hard to bring them around people and animals outside of their family.

14. Rhodesian Ridgeback

The Rhodesian Ridgeback is originally from Southern Africa. It has the ability to keep lions away from prey while the dog’s owner goes in for the kill. It is a somewhat domesticated hunting dog.

Ridgebacks make for a good family pet who is extremely loyal to them, but they are very standoffish to strangers. This breed is also known to be overly sensitive so it’s important they receive the proper training, or they may develop an aggressive side.

15. Bullmastiff

These dogs were originally bred to be guard dogs, so it comes as no surprise that they are so big and intimidating. They can grow to be rather tall and weigh up to roughly 130 pounds. There’s a lot of strength inside these dogs when they become aggressive especially. Naturally, they can have a bit of a temper which requires a lot of work with an experienced trainer to overcome.

In 2014, roughly 5% of fatal dog attacks were caused by this breed. They can be aggressive towards other dogs of the same-sex and cause a lot of property damage to your home if they are not supervised. They are very protective of their family and will attack if they feel they themselves or their owner is in a threatened position.

16. Cane Corso

The Cane Corso is an extremely aggressive breed. There are quite a few cases reported every year of serious injury. They are very independent and dominant and are known to be violent and aggressive to other dogs. They are massive in size and it’s not difficult for them to overpower some people and animals causing injuries that are likely to be fatal.

This breed needs to be kept busy and active otherwise they become irritated and stressed. They don’t typically get along well with other family pets and prefer to be the only animal in the home.

17. Dogo Argentino

If you were walking down the street and happened to see one of these dogs you may easily mistake it for a Pit Bull. However, the Dogo Argentino is much larger and more muscular.

They originated in Argentina and their purpose was to be used as hunting dogs. There is a possibility that this dog can attack, and it can be lethal due to their immense strength. Their strength is what makes dogfighters attracted to this type of dog. They are actually banned in the UK and Australia.

18. Japanese Tosa

The Japanese Tosa was originally bred to hunt large animals such as wild boar and puma. They were also bred for dogfighting in Asia. Because of their dogfighting tendencies, they are banned in Australia, Cyprus, Denmark, Iceland, Malaysia, Malta, New Zealand, Norway, and Turkey.

If these dogs are not properly trained at a young age they can turn on their owners in seconds time. It is not recommended that first-time dog owners get this type of dog. They are meant for experienced owners only.

19. Akita Inu

The Akita Inu, bred in the mountains of Japan, is a very independent and headstrong breed. They were meant to be hunting dogs, so their hunting instincts are likely to kick in while around smaller animals. They aren’t known to attack their owners but because of their size and power, they’re likely to do some serious damage if they would attack.

It’s important that these dogs are properly trained and socialized otherwise they pose a risk to the safety of other people and animals. It’s common knowledge that if a dog isn’t trained correctly, it can become aggressive and hurt people when they become out of control. It is not recommended that you let these dogs roam free out in the open where it has access to strangers and other animals.

20. Saint Bernard

Originally, the Saint Bernard was the breed used to guard the grounds of Switzerland’s Hospice Saint Bernard as well as helping to find and save those who became lost and injured during their travels.

In today’s day in age, the Saint Bernard makes a great family pet and isn’t known to have much aggression at all. Their only downfall is their size and weight which can cause serious injuries to people.

21. Basenji

You may not believe it due to its size, but the Basenji is actually a hunting dog. They may not be dangerous to many because of their strength and size, but they can give you a nasty bite.

They are known to be hard to train and most owners will say they find their Basenji to be completely unpredictable even with proper training. Unpredictable dogs can be very dangerous, so it’s best to leave the headstrong Basenji to the experienced owners.

22. Boer Boel

The Boer Boel, also known as the South African Mastiff is a very large and confident breed. The good news is that these dogs are wary of strangers which makes them great guard dogs and great around children. Of course, proper training and socialization are necessary due to their defensive nature.

Don’t be intimidated by their size though, they are usually very playful and affectionate with their family.

23. American Bulldog

The American Bulldog is a breed that is known to be courageous and fearless. They can be aggressive at times when they feel they are being threatened.

Surprisingly, this breed is very friendly and sociable even though they were initially meant for hunting large animals such as bears. Because of their muscular build and confident, headstrong nature, the American Bulldog may be difficult to train, and can often cause damage if they’re not careful.

24. American Bandogge

The American Bandogge is a mix between a Neapolitan Mastiff and a Pit Bull Terrier. They having something called British canine temperament which means they have a high stimulus threshold and pack mentality.

If these dogs are raised and trained properly, they are more than trustworthy with children, something like a babysitter. On the flip side, this dog is often bred for fighting purposes which will make them highly aggressive.

25. Wolf Hybrids

A wolf hybrid is a dog that has been bred with a wolf. Research has been done and nothing has proved that more socialization and proper training would make them better house pets.

However, there are some wolf hybrids that can be docile and have good temperaments. But there is a higher percentage of these dogs that are prone to attacking people and other animals. More often than not people will need to obtain certain certifications to own this type of breed.

26. Tosa Inu

These dogs are known to get as tall as three feet tall and up to 200 pounds. Sadly, this is another breed to add to the list of dogs that are bred for fighting.

These dogs are massive and are known to be quite dangerous if they get into the wrong hands. In fact, these dogs have been banned in several states in an effort to try and cut down on the breeding for dogfighting. It’s not recommended that this breed be with another of the same sex or smaller animals such as cats. Any animal that can run, a Tosa Inu will typically run after it.

27. Chow Chow

The Chow Chow is known for being extremely protective and possessive over their owners. They are extremely and fiercely loyal which makes them amazing guard dogs for their families. Although it has a cuddly bear-like appearance, it is very aggressive and unpredictable.

This breed can become aggressive towards strangers and they do not do well alone with small children or dogs.

28. Perro de Presa Canario

It’s very likely that you will become instantly intimidated by this dog, also known as the Canary Dog. This breed is extremely large, weighing up to 130 pounds.

This is another breed that was bred for fighting purposes. They are not recommended for inexperienced dog owners due to their natural aggression. In addition, they become more dangerous with other dogs as they are pack dogs. This breed is also banned in many countries because of many fatal injuries to people.

29. Gull Dong

These dogs are also known as the Pakistani Bull Dog. They are mostly bred in Pakistan and are usually adopted because homeowners believe they will guard their homes. This breed is the perfect guard dog however, they are not the ideal family pet.

They are very suspicious of strangers and can become very aggressive when protecting their home base. The Gull Dong would be well suited on a farm or in some type of working atmosphere as they need to keep themselves stimulated.

30. Tibetan Mastiff

If you’re looking for a reliable guard dog, this breed will be right up your alley. In Tibet, these dogs would be chained to a pole at as early as two months only in order to make them aggressive. They would then be used to guard an entire village.

These dogs become very attached to their owners and the ones they love. They guard them with their life. This breed is recommended for experienced dog owners only who can put the time into giving them the proper training.

31. Staffordshire Bull Terrier

This dog may be easily confused with a Pitbull as they share some of the same physical characteristics. Unfortunately, these dogs, like the Pitbull, and many others are bred for fighting purposes.

If you’re in the market to adopt one of these Terriers, it is not recommended that you bring them into a home with small children or other pets as their temperament is very unpredictable. This breed is also known to be very energetic, so they will need to get plenty of exercise.

32. Pharaoh Hound

Despite this dog’s particularly regal sounding name, the Pharaoh Hound is known for its aggressive tendencies. Just look at them you can tell they are slim, fast, and strong.

These dogs also have a high pretty drive, which means it’s not recommended that they be around small children or animals. If you’re looking for a guard dog, this isn’t the breed for you. They enjoy investigating new people and places. It’s important that early on they receive plenty of ongoing socialization to build their confidence.

33. Czechoslovakian Vlcak

The Czechoslovakian Vlak, also known as the Czach Wolf Dog was first bred in the military as an attack dog. Their temperament, trainability, and pack mentality are equivalent to that of a German Shepard. In addition to their jobs in the military, they are also used in search and rescue, tracking, herding, agility, hunting, obedience, and drafting.

These dogs are very smart and obedient. The good news is they will rarely attack a person or animal unless they are commanded to do so.

34. Neapolitan Mastiff

You will be amazed at the size of this dog- it’s incredible. They can reach up to 200lbs. These dogs have been known to kill, and it comes as no surprise considering their size.

They were initially bred to kill which has made them popular guard dogs amongst some dog owners. With that being said, overall, they are fairly calm and incredibly loyal.

35. The Moscow Watchdog

This particular breed of dog is a cross between another well known, and aggressive, breed of dogs. The Moscow Watchdog is a cross between a Saint Bernard, Caucasian Ovcharka, and a Caucasian Shepherd. They truly are massive and beautiful to look at.

These dogs were first bred in the Soviet Union, specifically designed to be military dogs fit for protection. These dogs were bred to serve and protect their owners and because of that, they have a particularly high rate of aggression which can be dangerous to those who are not experienced dog owners.

36. Newfoundland

The Newfoundland is another dog that was bred for military protection and war. Like most war dogs, the Newfoundland bonds quickly with its human companions. They absolutely love the water and because of their size the dog best in wide open and spacious areas. They do exceptionally well with children and are generally very friendly dogs.

They love to be around people and don’t do well alone for long periods of time. With that being said, it’s still crucial they get plenty of socialization skills.

37. Dogue De Bordeaux

Otherwise known as the French Mastiff, the Dogue de Bordeaux is a working dog that was originally bred in the Bordeaux region of France. These dogs were mostly used as working dogs, as their size, strength, and intelligence make them easy to train to do work around the farm.

They need to stay physically fit, so daily walks and plenty of activity is a must. This breed is generally friendly with proper socialization skills at an early age. With that being said, they are banned in certain areas and are not covered in homeowner’s insurance policies.

38. Bully Kutta

Mostly popular in Pakistan, the Bully Kutta is also known as the Indian Mastiff. Like many Mastiffs, the Bully Kutta is used as a protection dog. They surely are an intimidating breed.

Their size, strength and trained aggression have made the Bully Kutta one of the most popular watchdog breeds in all of Pakistan. This dog is often warned against being left alone with small animals and children. Its protective drive may work well for protecting territory and adult humans, but there’s always a margin for error.

39. Russian Black Terrier

The Russian Black Terrier has a particularly gruesome past. This is a fairly new breed of dog, having been bred in the 1920s. Another fact is that they hardly shed which is good for those who suffer from allergies. As far as research shows, the Russian Black Terrier is apparently the only dog that has ever been bred specifically to hunt humans.

It was bred in the former Soviet Union as a dog specifically used to keep prison camp detainees in line. Now, the Russian Black Terrier makes a particularly stunning guard dog, though it’s dangerous past should always be kept in mind.

40. Shar-Pei

Not only is the Shar-Pei one of the rarest breeds of dog in the entire world, but they’re also one of the most aggressive. The Shar-Pei was bred in China, particularly to be an aggressive dogfighter. For anyone who has a Shar-Pei, their aggression should be monitored carefully.

While they may be sweet to their owners, but they can prove to be pretty dangerous towards strangers. Due to their aggressive nature, it is not recommended that these dogs be left alone with small children as they may attack them. Shar Pei’s should constantly be observed to avoid any fatal injuries.

41. Beagle

Most people associate beagles with loud howling, short, friendly dogs. And while a well-trained beagle could be your best friend, the beagle is actually a dog breed that has a high rate of aggression.

Did you know that beagles were originally bred for hunting small game? Because of this, beagles today have a high prey drive and can become excited and aggressive quite easily. This means that small animals and children should be carefully monitored around this kind of dog. Overall, the Beagle is a very friendly and wonderful house pet.

42. Gull Terrier

The Gull Terrier is a popular, but rare, Pakistani breed of dog. It’s most well known for being one half of the Gull Dong, but the Gull Terrier is dangerous all on its own. Please be aware that this breed is not for the beginner dog owner.

They’re extremely aggressive, which is why they were used alongside the Bully Kutta in order to breed the popular Pakistani guard dog, the Gull Dong. These particular dogs, like other Terrier breeds, should always be watched around small animals and children.

43. Akita

Most people don’t know the difference between the Akita and the Akita Inu – however, the Akita is the American bred version of the Akita Inu. They’re quite similar, but still two distinct breeds of dogs.

The Akita is an incredibly strong-willed, beautiful dog that has been bred for hunting. They are an independent breed and that makes training them particularly difficult. Akitas, when not trained properly, can become aggressive and dangerous towards others.

44. Bedlington Terrier

This is an interesting looking dog. It is actually in the official Dangerous Dogs list in the United States. They’re an incredibly stubborn breed of dog, and because of their breeding, have a high prey drive. These particular dogs can be docile and friendly when well trained and socialized as puppies.

However, the Bedlington Terrier can be particularly dangerous around small animals and children, due to their prey drive and instinct to hunt. They also have an infamous temperament issue, which can cause them to lash out and be more dangerous. This breed needs plenty of attention to their training at a young age. They are recommended for experienced dog owners only.

45. Korean Jindo Dog

Bred on Jindo Island in Korea, the Jindo is a hunting dog that’s well known for its bravery and loyalty. Of course, hunting dog instincts mixed with bravery make a particularly dangerous dog, especially if it isn’t trained properly.

Like most breeds of primitive dogs, the Jindo is quite stubborn, which means it can be hard to train. Inexperienced trainers may find that the Jindo is more than they can handle. Because of this, most of these dogs are left untrained, unpredictable, and aggressive.

46. Belgian Laekenois

This strong and sturdy dog comes from the family of Belgian herders and this one is the rarest. One of the most distinguishing things about this dog is the blackening around the nose which indicates a sharp and keen sense of observation. These dogs are pretty fierce watchdogs with their protective nature.

The Laekenois takes a while to warm up to strangers but becomes friendly with passing time. Keep these dogs active, otherwise, they can get grouchy.

47. Catahoula Leopard Dog

Literally meaning “sacred lake” in Choctaw, these powerful and assertive dogs have an interesting story and have been found to originate in the state of Louisiana.

These dogs are great family dogs but do not cross them. According to the American Kennel Club, they don’t allow mistreatment. When training these dogs, its imperative that they are dealt with using firmness.

48. Caucasian Shepherd Dog

For centuries Caucasian Shepards were used by landowners to protect them and their land from trespassers or the odd wild animal such as wolves and coyotes. Obviously, this is one tough dog if it can fight off predators like that.

The Caucasian Shephard differs greatly from region to region, but for the most part, they branch off into two types: The Mountain type- which has a longer and thicker coat, and the Steppe type which is lighter in mass and with a shorter coat.

48. Chesapeake Bay Retriever

These powerful dogs can reach between 21 – 26 inches at the shoulder, with a male weighing up to 80 pounds. While their chocolatey coat can make them appear harmless, these breeds are rather emotionally complex dogs making them prone to bouts of aggression.

These hunting dogs have a mind of their own but a well socialized and trained Chessie can be an excellent companion. Just don’t push it over the edge.

49. Thai Ridgeback

The Thai Ridgeback, with its sleek and athletic build, can be formidable hunters and guard dogs. Without an experienced dog owner, these dogs can get out of hand pretty quickly. They require a great deal of assertiveness and patience. Consistency is key.

The Ridgeback thrives on independence and self-sufficiency. They are naturally inclined to hunt for heir own food and are highly intelligent. It’s safe to say that this breed is no lap dog.

50. Romanian Mioritic Shepherd Dog

Belonging to the LGD group – Livestock Guarding Dog, these dogs are incredibly reliable and loyal to their owners. While these are great qualities, they are accompanied by more aggressive traits. Fiercely protective, these dogs can easily mistrust strangers very.

It’s because of is temperament that these dogs get basic training and a strong sense of discipline instilled in them. Their high energy requires them to be walked daily. These dogs need large spaces to roam free and a lot of exercise.

51. Estrela Mountain Dog

This is one old dog breed and is believed to be the oldest one of the LDG breed. With high energy and fierce tendency to protect, this dog is perfect for large areas and landscapes such as farmlands or just large properties in general.

This dog is wildly protective of its owner and extremely docile with the ones it loves, but strangers, beware, this dog will stop at nothing to protect its family and its land.

52. Hovawart

This is no easy breed and not is exactly ideal for the new dog owners. These dogs lean towards the stubborn side and need quite a lot of attention. For owners who do spend their efforts on teaching this kind of dog the appropriate behavior, the reward is having an incredibly loyal pet.

It’s important to remember that these dogs love a job. Without it, they can get aggressive. They are amazingly creative worker dogs with high levels of energy. Hovawarts are wonderful for search and rescue organizations, therapeutic activities, obedience trials, agility trials, flyball and also make great service dogs.

53. Beauceron

This dog is not for the faint of heart. Beaucerons are robust and muscular dogs with a strong presence. Reaching as high as 27 inches at the shoulder, these dogs can do quite a bit of harm. The American Kennel Club has described these dogs as “well-chiseled”, with dark brown eyes that “project an expression breed fanciers describe as frank and confident.”

It is important to stay dominant with these dogs as they can very easily dominate a weaker owner. It is good to note, however, that once these dogs are disciplined, they are excellent with the smaller and defenseless.

54. The Finnish Spitz

This little fox-like bushy dog is pretty fierce for its size. Sharp and alert ears make this dog highly observant. Finkies or Fins as they are nicknamed can be an excellent combination of a loving friend and a watchful guard.

What makes these dogs extra fierce is their bark. This is no quiet breed and in Finland, owners actually hold barking contests. The winner gets crowned “King Barker”. So if you’re looking for more than one way to scare off unwanted visitors, a Fin might do the trick.

55. Griffon Nivernais

Originally bred to hunt wolves and wild boars in the fourteenth century, these dogs have a ferocious past. Now, a little calmer, a Griffon Nivernais still carries a predatory instinct. This French breed is a little larger than most French hounds and stands between 21- 23 inches.

It may not look like the most agile and speedy type of dog, as this dog bred more for endurance than speed.

56. Kishu

This is Japanese hunting dog has been described as extremely courageous. They have powerful predatory instincts and can often be spotted hunting smaller animals. They were originally bred for boar and deer hunting.

If these dogs are not socialized well, they can easily become quite combative, but with the necessary training, they are devoted and protective dogs. Just be wary when they meet strangers.

57. Great Pyrenees

Do not be fooled by the zen-like attitude of the Great Pyrenees. These dogs seem very calm but can swiftly shift into action when threatened. Their immense power makes them a deadly opponent, especially with their height of over 32 inches at the shoulder and weight of more than 100 pounds.

The Great Pyrenees is related to many other large LGDs such as the Newfoundland dog, the St. Bernard and the Polish Tatra Sheepdog.

58. English Mastiff

This English Mastiff has been compared to the Bull Dog. Both these dogs can be just as ferocious, both can enter into combat with the temper and eagerness to attack, but while the Bull Dog, in a blind rage, might bite the hand of his own master, the English Mastiff can distinguish perfectly between friend and foe.

These back-masked giants are massive and stand at about 30 inches. The rectangular body has heavy muscles and it’s broad and large head can be rather startling when staring at straight on.

59. Shiba Inu

Essentially a popular companion dog, the Shiba still has a predatory instinct as it was bred as a hunting dog. The dogs do not take kindly to provocation and can show aggression, but above all, when expressing emotion, these dogs emit what is labeled as the “Shiba scream.” This high pitched scream can ward off unwanted guests and can also serve as a strong warning sign for mishandling.

The Shiba is Japanese (it is a Japanese breed!) for Brushwood, which is a type of shrub or bush that turns red in the fall. Many people believe that is what was kept in mind when naming the dog. On the other hand, in Nagano, an ancient Japanese dialect, Shiba also means small. Either way, this “Little Brushwood Dog” packs a punch.

60. Boston Terrier

While the Boston Terrier is essentially a playful dog, it is still highly protective. It is that “eager to please” approach that makes them actually rather aggressive and territorial when needed. Bred initially for fighting, these dogs only later became companion dogs.

Early training is essential as they can very quickly get out of hand. Their edginess can turn into a nasty aggressiveness if not disciplined properly.

61. Bernese Mountain Dog

These working dogs were brought to Switzerland about 2000 years ago by the Romans for the purpose of guarding large mountainous terrain, so it seems only natural that these dogs should have quite a bit of fight in them.

Like any worker dog, this breeds is fiercely loyal and will attack intruders with zero hesitation. Best for farms and larger suburban areas, these dogs need a lot of roaming area.

62. Berger Picard

Left to their own devices, these dogs can be highly destructive creatures. They are tall and strong animals that can take down a thread pretty easily.

Ideal for active owners, their agility, robustness and endless energy can be put to excellent use. If idle, these dogs are less pleasant to be around.

63. Lhasa Apsos

It might be impossible to believe but these dogs were originally bred to be indoor monastery-sentinel dogs by Tibetan Buddhist monks. Yes, these tiny dogs are not scared off easily. If these dogs are left untrained, they can turn into aggressive little monsters.

Highly suspicious towards strangers, they are eager to express their dissatisfaction with their owners. They can also very stubborn and have been seen to lie flat on the floor without moving when they are not in the mood for walking.

64. Chihuahua

It’s not always about size. The Chihuahua is one tiny dog with a big dog attitude. While it can weigh no more than 6 pounds, a Chihuahua’s alert nature can make it one feisty little watchdog. Out of all the little dogs, this one is probably the fiercest.

Without training, this little thing is capable of ruling your household, and according to The American Kennel Club, can be, “a little Napoleon.” when left undisciplined. Be wary when kids are around, smaller dogs do not take kindly to the playfulness of young children and can feel very threatened.