While domesticated dogs are almost always extremely friendly and amicable, on rare occasions, dogs can be dangerous. There are many different breeds of dogs, but the most dangerous dog breeds are quite well known, however looking at the top 10 most dangerous dogs by bite fatalities came up with some interesting results.

The Journal of the American Veterinary Medical Association conducted a twenty year study on the most dangerous dog breeds, and here are the top 10 most dangerous dog breeds based on the amount of fatalities they have caused:

10. St Bernard

At #10 is the gigantic St Bernard. With only 7 fatalities in this study, it’s not surprising as St Bernard’s were original bred as rescue dogs. Adult males can measure about 30 inches tall (75 cm) and weigh a whopping 155 pounds (75 kgs), they have a very passive temperament and are mostly a danger due to their massive size as adults.

9. Great Dane

The Great Danes are the 9th most dangerous breed according to the study. With a total of 7 fatalities in the periods in between 1979-1998, the Great Dane or German Mastiff is known to be one of the largest breeds of dogs ever domesticated. Although they have a low prey drive (carnivorous animals feeding instinct), they were initially bred for hunting animals. Their immense size (with some adults measuring up to at least 30 inches (76 cm)) makes them an obvious threat around children and even adults.

8. Chow-Chow

Somewhat surprising due to their small frame and stature, the Chow-Chow was reported to have been responsible for 8 fatalities in the journal’s study. With an average Chow-Chow weighing about 60 pounds (28 kilograms) and only growing as large as about 20 inches (52 centimeters) the Chow-Chow is unfortunately known to have a very aggressive personality, especially around strangers.

They are usually held as pets, and due to their size they can be kept in apartments. The danger rests when they lack exercise or are just generally bored, and will sometimes lash out at strangers and even owners due to boredom.

7. Doberman

Known to be one of the most aggressive breeds of dogs ever, the Doberman Pinscher was one of the most recognizable dog breeds as they were used extensively as guard dogs. They were bred for the specific purpose of guarding their masters, and thus had to be aggressive but also intelligent.

Trained properly, these dogs can become very loyal to their masters, but aggressive towards perceived threats to their owners. Being responsible for 9 fatalities, most of these were notably in defense of their owners.

6. Malamute

Malamutes are commonly mistaken for another dog further up on this list, the Husky, but have many differences. They are quite large with adult males weighing around 85 pounds (34 kilograms) and standing about 25 inches (62 centimeters), however are known to be more passive due to their use as work dogs, pulling sleds and helping with manual labour. However, like the Great Dane their size makes them unsafe around children or small animals and the study found they were responsible for 12 deaths over the 20 year study period.

5. Wolf-Dog Hybrid

Unsurprisingly Wolf-dog hybrids (Wolf X) are known as the 5th most dangerous breed of dogs. With 14 listed fatalities in this study. Wolves themselves are ancestors of the modern domestic dog, and are known as one of the most dangerous predators in the wild even today. Even with proper crossbreeding, domestication, and training Wolf-dog hybrids maintain much of the prey drive of their wolf genetics making them quite dangerous to keep as pets.

4. Husky

Huskies are one of the oldest breeds of dogs thought to exist in the world. Like their Malamute cousins they are used primarily as sled dogs, and must be constantly active. With a total of 15 fatalities linked to Huskies in the study conducted, they are definitely known to be aggressive, but this has been linked to poor training/obedience issues as Huskies rate as one of the most intelligent canines in the world. Given their close relation to the grey wolf however, they do maintain a somewhat high prey drive.

3. German Shepard

Another commonly recognized dog makes this list. German Shepherds are a fairly new breed of dog, only dating from about 1885, where a society in Germany worked towards creating a perfect breed to protect herds in rural communities. A fully grown adult German Shepard can weigh 82 pounds (38 kilograms) and stand at about 25 inches (62 centimeters), about the same size as a Malamute.

Also like the Doberman, their high intelligence and aggressiveness makes them sure picks as guard and police dogs. With 17 fatalities attributed to them, they are the third most dangerous dog breeds.

2. Rottweiler

Coming in at #2, the Rottweiler was responsible for 39 fatalities in this study. Another very old breed the Rottweiler is one of the oldest herding breeds in existence. As with most old breeds, their prey drives require much training to dampen.

Adult males have about the same dimensions as the German Shepard, however they are much heavier, with some being able to weigh around 110 pounds (50 kilograms). Their temperament is usually passive and attentive, but are known to be prone to aggressive outburst.

1. Pit Bull

To anyone who knows dogs, the American Pit Bull Terrier is no surprise at #1 on a list of deadliest dogs. In this study the Pit Bull stood far ahead of all the other breeds with 66 fatalities attributed to it. Known for their extremely aggressive nature, many states have legislation banning the breeding of pit bulls.

Furthermore they are known to be bred for the highly illegal sport of dog fighting. Therefore, it’s no real surprise that Pit Bulls are known as the #1 deadliest dog based on bite fatalities.