Why is my little dog so aggressive? Let’s Explore

Lack of Training for Small Dogs

Smaller dog owners reported being more inconsistent with, and engaging less in, training and play activities than larger dog owners.

In other words, small dog owners spend less time training their dog and engaging their dog’s brain.

This makes sense to me according to what I’ve seen.

When I see big dogs who bark or jump, or otherwise act act aggressively, the owners do something about it.

They have to because a large dog can do a lot of damage to another dog or person. A big dog acting that way is seen as scary and threatening.

The dog may even get reported to animal control if it’s bad enough or happens repeatedly.

When I see small dogs behaving the same way, usually nothing is done about it in regard to controlling the dog or situation.

The small dog owners usually just laugh nervously and apologize, thus enabling the behavior instead of correcting it.

It’s Frustrating or Embarrassing to You

Although plenty of small dog owners allow their small dogs to lash out and act inappropriately towards other dogs, I almost always see owners of dogs displaying small dog syndrome acting or verbally being apologetic.

Based on my own experience, I can say it’s no fun when I’m walking along having a nice day and all of a sudden my small dog yanks on my arm and causes a scene.

I don’t believe that any small owner PREFERS that their small dog act mean by growling, barking, or lunging at other dogs or people.

My suspicion is that these owners just don’t know what to do.

They don’t understand dog body language (their own dog and others approaching) enough to know how to avoid negative situations.

They don’t understand how to teach their small dog to stop barking and lunging.

Or maybe they have tried one or two techniques that didn’t work so they gave up.

Punishing a Small Dog Can Increase Fearfulness and Reactivity

Increased anxiety and fear was related to a more frequent use of punishment* in smaller but not in larger dogs.

Note: I combed the internet and was not able to determine what the definition of “punishment” was for the purpose of this study.

However, when people talk about punishment in dog training, often they mean adding something to make the likelihood of a behavior go down (positive punishment), such as using leash jerks, alpha rolls, or hitting the dog.

I’m assuming that is also what they mean in this study but acknowledge that I can’t be sure and could be wrong.

In other words, if a small dog owner used punishment, it was more likely to scare a dog and make them anxious.

It seems logical to me that a small dog who is more scared and anxious is more likely to act out negatively.

So I’m not saying it’s impossible for a small dog to be genetically predisposed to anxiety, poor behavior, and aggression.

BUT that is just as likely to affect large dogs so the behavior difference seems to come down to that nurture thing I was talking about.

Cesar Millan Controls a Small Dog with Big Attitude

With their large, muscular bodies, dogs such as rottweilers and pit bulls, especially those that are trained to act menacingly, may seem like the scariest of their species. But evidence shows that smaller dogs can actually be more aggressive than many of their outsized counterparts.

First, its important to define what counts as tiny for a dog. “Small dogs in the less-than-20-pound [9 kilograms] range tend to be more reactive,” said James Serpell, director of the Center for the Interaction of Animals and Society at the University of Pennsylvania School of Veterinary Medicine. For example, dachshunds, Chihuahuas and Jack Russell terriers are the most likely to attempt to bite, according to a 2008 study in the journal Applied Animal Behaviour Science that surveyed the owners of more than 30 dog breeds. Other aggressive behaviors seen in little dogs include growling, snarling and lunging. There are a few theories for why this is the case.

Small size may make dogs more fearful, and they may lash out in self-defense, Serpell said. Tiny breeds may be more likely to react defensively because they have more to be afraid of.

Alternatively, small dogs reactivity could be a result of their owners behavior. “Owners tend to infantilize small dog breeds and think of them as being like helpless infants,” Serpell told Live Science. Pet owners may be overly protective of small breeds, so they may not socialize them or teach them how to properly react to stressful situations.

Aggression could also be baked into the pups evolution. “If youre attacked by a Chihuahua, obviously the consequences are much less significant than if youre attacked by a Great Dane or a Siberian husky,” Serpell said. In other words, over the millenia, humans may not have bothered to breed aggressive behaviors out of little dogs because the consequences werent as dire as they were for being attacked by sizable hounds.

That last theory is supported by studies that have found a link between aggressive behavior and the growth factor gene that makes small dogs small. The association could be coincidental, but research has shown that small dogs arent just more extreme in their aggression-related behaviors; compared with large dogs, small dogs tend to have more severe separation anxiety, usually bark more and are more likely to urinate in the house, Serpell said. This gives credence to the theory that genetics plays a role in little dogs extreme behavior.

Scientists arent sure which of the theories are correct because they havent studied the root of little dogs fierce behavior yet, Serpell said. All of the theories could potentially play a role.

Some tiny breeds are an exception to the rule. One example is the Coton de Tulear, also known as the Royal Dog of Madagascar. This dog is small, white and fluffy, similar to a bichon frise.

“For some reason, that breed seems to have quite subdued behavior across the board, but it also has all kinds of medical problems,” Serpell said. “Its unclear whether thats because they maybe lack some critical genetic factor. Or it could be related to the fact that theyre just more unhealthy and less physically able to react strongly.” RELATED MYSTERIES

Some aggressive behaviors can be addressed safely while living with the dog, but a professional dog trainer should be the one to work on correcting the behavior, according to VCA Animal Hospitals, a system of animal hospitals.

Body size may not be the only attribute of small dogs that is associated with aggression. Lower height alone is associated with undesirable traits in some breeds, according to a 2013 study in the journal PLOS One. For example, dog breeds with shorter legs are more likely to be fearful of unfamiliar dogs and to have owner-directed aggression. Its unclear why this is the case, but it may be something to keep in mind when youre looking for your next pet.

Editors Note: Updated on June 8, 2021 at 3:33 p.m. EDT to fix the name of VCA Animal Hospitals. It is not Veterinary Centers of America, as previously stated.

Tyler Santora is the Health & Science Editor at Fatherly and a Colorado-based freelance science journalist who covers everything related to science, health and the environment, particularly in relation to marginalized communities. They have written for Popular Science, Scientific American, Business Insider and more. Tyler graduated from Oberlin College with a bachelors degree in biology and New York University with a masters in science journalism.