If you live with a dog you, probably have noticed that your pup barks at some people but is completely cool with others. Why do dogs have different reactions to different people? Do they know something about them that you don’t?

In this article we will tell you why your dog barks at some strangers but not at others and wait until you hear what we have to tell you about why dogs bark at certain dogs, that’s a lot more surprising than you may think.

1. People smell

Dogs see the world primarily through scent and a dog’s sense of smell is between 10 000- 100 000 times better than that of humans. Because of this disparity, it’s hard to imagine all the information that our canines can gain from a person’s scent.

People have different scents and your dog may bark at them because their smell could be off-putting to your dog. For example, your dog may bark at some people because they have the scent of another dog or cat on their clothing. It’s especially true when someone has a dog of their own or they may have the scent of something unfamiliar like cigarettes.

Beyond that, some dogs have an aversion to strong smells like vinegar, perfume, alcohol, citrus, or bleach. You may think the scents will fade away after a few hours but your dog will be able to smell them for a long time afterward. Likewise, pheromones that the person is giving off could be alerting the dog to a threat as well.

It gets even more interesting, dogs can sense when we are nervous because our bodies produce certain stress-related chemicals and hormones that have distinctive odors.

When someone who makes you nervous approaches you, your dog may realize that you are not at ease and they bark at them to ensure you stay safe.

2. A person’s looks

Dogs don’t see details or color as well as we do but they do still depend on vision to some degree. This is why looks can set off different triggers in dogs.

There can be something different with the person that unsettles your pup, the person may wear a hat, have a beard, talk loudly, wear baggy clothes, or rattling jewelry.

Some dogs feel afraid and insecure if a person’s features or movement style are unfamiliar to them or reminds them of a threat like a stranger who is standing in a way that appears imposing and aggressive to the dog or a person who makes sudden movements. To avoid these situations, make sure your dog gets exposed to lots of different people.

Now let’s talk about why dogs bark at my dogs but not others.

While humans communicate using words, dogs mainly communicate through their body language and scent. Your dog may bark at some dogs because they show threatening body language. You may not notice their body language but subtle signs like freezing of the body, whale eyes, tense mouth, and wrinkled nose may be off-putting to your dog. Dogs communicate with each other in ways that we don’t understand, that we are just completely blind about. A dog will see something in another dog’s body language r pick up scent clues that signal something the first dog either likes or dislikes.

Dogs can sense those subtle o cues or scents from a significant distance away and this is why some small dogs are aggressive toward big dogs. If your small dog barks at larger dogs or are aggressive towards them, it could be because they feel threatened and are fearful of their imposing appearance.

Another reason that a dog may take an immediate dislike to another dog is that dog’s historical experience. If for example your pooch was attacked by a big white dog in the past, he may exhibit intense fear and aggression towards large white dogs. Likewise, dogs may bark at each other out of excitement.

If another dog shows signs of excitement in their body language like wagging tail or bowing their front leg, your dog may bark at them to indicate their desire to play with them but rest assured that you’ll know when your dog barks out of aggression versus excitement and aggressive barking is often accompanied by growling or tense body language. And it’s important to remember that although dogs are pack animals, it doesn’t mean they want to socialize with any dog. Think about it, do you want to talk with any person you meet on the street?

Just like humans, dogs simply don’t like bonding with certain dogs, if your furry friend is aggressive wards some dogs, don’t keep forcing them together expecting them to arm up to each other.

And finally, many dogs bark at each other because they are being protective.  This is especially true when other dogs are on their territory, your dog is guarding you as a member of their pack.