10 Most Aggressive Dog Breeds: Temperament Ratings and Information

Looking to Adopt?

Are you are looking to get a new puppy to keep as a family pet and would like to know which breeds may not be the safest for children? In doing this research, I found that different organizations and “experts” have differing opinions as to which dog breeds are the “most aggressive,” so below, I've listed the 10 that most sources seem to agree on.

How Canine Aggression Is Defined

Dog aggression is typically defined as dangerous behavior directed at another individual (like a human or another dog). Aggressive behaviors include barking, biting, lunging, snarling, etc. The causes of these behaviors can range from territorial defensiveness and protectiveness to fear and social anxiety.

How I Determined Which Dog Breeds Are the Most Dangerous.

The 10 breeds listed below had some of the lowest overall passing rates in conducted by the American Temperament Test Society and are sorted in order from lowest to the highest percentage of individual dogs that passed. Breeds with the lowest passing percentages frequently showed signs of aggression, panic, or extreme shyness during the test. The American Temperament Test is not a predictor of actual aggression such as biting or attacking.

While there are breeds with even lower passing percentages than those mentioned in this article, I've decided to limit this list to the 10 breeds that are most frequently ranked as highly aggressive (i.e., these are breeds that are most commonly considered “aggressive” or “dangerous” and/or are included in breed-specific legislation). Each breed on the list is discussed in greater detail in the sections below, and overall passing rates are included for each.

1. Chihuahua

is the smallest breed of dog registered with the American Kennel Club (AKC) and is thought to be the smallest in the world. They are included in the “toy” group of dogs and usually range from around four to six pounds. They can have short or long hair of just about any color, and their coloring can be solid, marked, or splashed.

Having originated in the Mexican state of Chihuahua—hence the name—the breed is considered to be one of the oldest in America. It was first introduced to Europe by famous colonizer Christopher Columbus.

Chihuahuas are typically very loyal and devoted to their owners, but they are generally one or two-person dogs. They can be devoted to the point of jealousy and may bite or snip at individuals who come too close to their owner. They are very temperamental and are not known to be particularly child-friendly. Because they do not usually like strangers, they bark often and can serve effectively as alert-style “watch dogs.”

2. Basenji

Basenjis are one of the oldest of the AKC breeds. Their lineage can be traced from the ancient Egyptian civilization to the African Congo where they were used by Pygmy hunters to chase their game into nets. They would run in packs and were often referred to as “barkless” dogs as instead of barking they make more of a yodeling sound.

are small, graceful dogs standing 16 or 17 inches at the shoulders and weigh around 22 to 24 pounds. They have a very short shiny coat of brown, red or brindle with white and have a tail that is tightly curled over their back. They have a wrinkled forehead and almond shaped eyes. Basenjis are fastidious and clean themselves much like a cat. They are known as a hypoallergenic dog with very little shedding and less than the normal “doggie smell”.

They are rather suspicious natured dogs and have a strong “prey” drive. They want to dominate other dogs, especially male dogs and can be very protective of their toys and food. You may want to be very watchful around children as the Basenji don’t particularly like being grabbed or squeezed and it has been recommended NOT to sneak up behind them.

are small, graceful dogs standing 16 or 17 inches at the shoulders and weigh around 22 to 24 pounds. They have a very short shiny coat of brown, red or brindle with white and have a tail that is tightly curled over their back. They have a wrinkled forehead and almond shaped eyes. Basenjis are fastidious and clean themselves much like a cat. They 

3. Dachshund (Standard Smooth)

is categorized as a member of the “hound” group by the AKC. Ranging in size from around 8 to 32 pounds, they can have long or short hair of just about any natural color.

They originated in Germany in the 17th century and were used primarily to hunt badgers. By the end of World War I, they were on the verge of extinction, but populations have since recovered, and they are now one of the most popular dogs in America.

The Dachshund is susceptible to “small dog syndrome,” which basically means that it often tries to make up for its small size with a large attitude. This can lead to a variety of behavioral issues. If socialized at an early age, they can do well with children, but they do not enjoy rough play. Take caution with small pets, such as mice, rats, and hamsters, as  have a strong hunting instinct toward this type of animal.

4. Chow Chow

The Chow Chow is listed as a medium-sized dog in the “non-sporting” group by the AKC. They typically weigh between 45 and 70 pounds and have long, thick coats that can come in red, black, blue, cream, or cinnamon colors.

The exact origin of the Chow Chow is unknown, but it is believed that they originated thousands of years ago in either China or Mongolia where they were most often used as hunting and herding dogs. They became popular in the U.S. during the 20th century when President Calvin Coolidge kept one as a pet.

Chow Chows tend to have dominant personalities and can become assertive at times. Because of their assertiveness, they are not recommended for first-time dog owners.
Strong guidance and firm training are required in order to raise a well-mannered Chow Chow. It has also been noted that they do not have good peripheral vision, so they can be startled easily.