In outlining the top aggressive dog breeds, I would like to make a distinction between the top aggressive dog breeds and the top most dangerous dogs. By this I mean there are of course those aggressive dog breeds that make the headlines because they are dangerous. These are the large, powerful, aggressive dog breeds that were usually bred for fighting or hunting. When they are aggressive, they hurt, maim or even kill people and other dogs.
But when discussing the top aggressive dogs, there are certain breeds that are more likely to act aggressively through biting people or other dogs, but are not particularly dangerous due to their small size. So in outlining the top aggressive dogs, I am going to discuss the breeds most likely to act aggressively as these are the little pint-sized dynamos you are more likely to encounter in day to day life.
Chihuahua
Though he may be little, he carries a big stick! Maybe it's due to their small size leading to some kind of 'Napoleon complex', the Chihuahua seems to make up for its lack of size in out and out feistiness to be on the top-ten list of aggressive dog breeds. At under six pounds fully grown, these nervous little fellows are especially prone to snap at children. They are famous for their unwavering, if not a bit emeshed, relationships with their owners that can reach the point of an obsession. Is it any wonder fame-obsessed celebrities seem to favor them? They lash out aggressively at anyone who comes near. And size is no matter, they will just as well snap out at dogs their own size as much larger dogs. Unfortunately, because they are so small and harmless looking, their owners often will tolerate aggressive behavior in these mighty mice, thinking such behavior is funny or cute and allow if not encourage behaviors in Chihuahua's they would never allow in a larger dog.
Beagle
He may be Charlie Brown’s pet Snoopy, but who knows how often Snoopy may have bit Charlie Brown over the years. The beagle is a plucky hunting breed of a small to medium size. Due to their natural instinct toward ferreting out or chasing down wild animals, the Beagle can sometimes be excitable and impulsive, making them very hard to train and causing them to act out aggressively at times. If the Beagle manages to catch a waft of scent on the air, they can often become completely unresponsive and unmanageable by their owner. Despite this, given the proper discipline and respect, the Beagle can make a wonderful family pet.
Pekinese
The Pekinese is a breed of dog that descends from Chinese imperial royalty. In fact, up until 1860, only members of the Chinese Royal Imperial Palace could keep a Pekinese. They were not imported out of the country until the 1860's when soldiers of the Second Opium War brought some back to England and France. These pampered and over-indulged former members of the royal palace are not particularly fond of strangers or children and they will lash out aggressively toward other dogs no matter what their size.
The Shar Pei was at one time one of the rarest dog breeds on earth. Originally born and bred in China, the wrinkly Shar Pei may be related to the Chow Chow, as both of these breeds display the distinctive purple tongue. Though they may look cute and pudgy, the sinister reason behind the Shar Pei's loose skin allowed the Shar Pei to twist and bite during dog fights, allowing it to fight back even when its opponent had a good grip on it. In line with their fighting pedigree, the Shar Pei maintains its natural innate aggression and guarding qualities as well as the serious temperament that goes with it. These qualities make the Shar Pei one of the most aggressive dog breeds.
Bull Terrier
The Bull Terrier's funny shaped egg-head may look harmless, but looks can be deceiving. The Bull Terrier's history is actually very similar to the Pit Bull, the infamous breed used in bloody baiting sports. The Bull Terrier was particularly good at what were known as "ratting games" where a Bull Terrier would be thrown into a pit of rats and dispatch them mouthfuls at a time. Though today's Bull Terrier's are more tame than their medieval cousins, they still maintain that fighting spirit. If not trained properly by a dominant owner, the Bull Terrier can become bossy and aggressive towards other dogs. They are also prone to certain health issues, such as obsessive compulsive disorders and deafness.
Cocker Spaniel
It's hard to imagine anything more docile and Disney-like than the floppy eared, doe eyed Cocker Spaniel. But this extremely sensitive breed of dog can often border on being neurotic. Proper socialization is ultra important for Cocker Spaniels, but even the best, most patient training cannot always overcome the genetic rage syndrome this breed is known for. Cocker Spaniels afflicted by this rage syndrome will lash out aggressively with little provocation. I can attest to this as of the three or four occasions I've ever personally been bitten by dogs, two of the incidents involved Cocker Spaniels! After viciously lashing out at someone or another dog, they can suddenly revert back to placid, docile pets once again, acting as if nothing happened. There is no cure for rage syndrome, though anti epileptic medications have sometimes been effectively used to treat the Cocker Spaniel, one of the most aggressive dog breeds.
Dalmatian
With the 1961 release of 101 Dalmatians, and the popular remake in 1996, the Dalmatian breed experienced an unprecedented rise in popularity. Unfortunately, many people purchasing the dogs had little idea of the breed or their propensity for aggression. A medium sized breed, the Dalmatian can reach weights of up to 70lbs. The Dalmatian was bred in the former Yugoslavia to accompany guard coaches. And of course their history with fire fighting is well known. The Dalmatian is an especially protective and independent breed and not really suitable for homes with small children. Like other high-strung dog breeds, the Dalmatian can become destructive and misbehave when not exercised properly.
Jack Russell
The Jack Russell breed gained fame as Frasier Crane's pet Eddie on the long-running television series Fraiser. The Jack Russell is a working terrier and has only recently been kept as a house pet. This sturdy breed was originally bred to track down foxes and pursue vermin underground. When they become bored or when improperly socialized, the Jack Russell can be dangerous. Though they rarely grow larger than 20 lbs., the Jack Russell has a tenacious temper, coupled with savage jaws, and they never back down from a confrontation, no matter the size of their adversary.
Chow Chow
The Chow breed is thought to be one of the most ancient dog breeds on the face of the earth. Though it resembles as much cuddly teddy bear in appearance as ferocious canine, it is naturally very aggressive and notoriously unpredictable. Due to its naturally deep set sunken eyes, the Chow has very limited peripheral vision, which makes it very easy to unintentionally startle this dog. It is intensely loyal to its owner and very suspicious of strangers. Some claim its aloof nature rivals that of cats. Weighing up to 70 lbs., the Chow was originally used for hunting and guarding in its native China.
Dachshund
The word Dachshund means literally 'badger dog' in German. They were originally bred to dispatching badgers, which if anyone knows badgers, they are pound for pound one of the most ferocious creatures on earth. To meet this foe, the Dachshund had to be every bit as ferocious as their wild adversary to stand any chance of surviving a confrontation, much less dispatching a badger. Often made fun of as a 'weiner dog', the long slender torso was actually so it could slide into badger tunnels to pursue them in their burrows. Generally weighing in at around 30lbs., the Dachshund is naturally willful and snappy. There have actually been studies to show the Dachshund is more prone to aggression against people and other animals than either Rottweilers or Pit Bulls, with some researchers concluding they are the most aggressive dog breeds of all.