Understanding dog behaviour

Why Do Dogs Sniff Each Other

Max. D Gray
By Max. D Gray. Updated: January 16, 2017
Why Do Dogs Sniff Each Other

You'd have to be blind not to notice this! Every time we take our dog out for a walk and we run into another dog, the ritual begins: a fearful approach, tail wagging or alertness and, then, the respective backside sniffing. For the less knowledgeable, this verges on the perverse and peculiar; however, it is the most natural behavior there is and you should not try to suppress it. Instead, try to understand what is behind this reaction.

Are you wondering: why do dogs sniff each other? Keep reading because at OneHowTo.com we?ll explain how.

You may also be interested in: Why do Dogs Sniff Urine?


  1. A matter of chemistry
  2. How does your dog process all this information?
  3. Do not prevent your dog from doing it!

A matter of chemistry

We all know that dogs have a highly developed sense of smell that is infinitely superior to our own. It is this very quality that allows dogs to determine a wealth of information from sniffing another's anal area. By doing this they can tell the emotional state of the dog at the time, what they've eaten lately, if it is a male or female and their condition. Their nose allows them to thoroughly analyse any fellow dog in seconds.

But, why do dogs sniff each other's butt? We know that you think it's unpleasant; however, at the sides of the anus are two small balls called anal sacs. These secrete all the chemicals that allow another dog to obtain this information. Therefore, by sniffing each other, they are showing each other a kind of chemical I.D. card.

Why Do Dogs Sniff Each Other - A matter of chemistry

How does your dog process all this information?

The odour from secretions emitted by the anal sacs vary in accordance with the dog's genetics or immune system. If a dog is feeling unwell, another dog can pick up on this by smell alone.

In order to process all this data, dogs have an auxiliary olfactory system called the Jacobson's organ, which allows them to decrypt chemical messages in the anal area and also on other residues - in the urine of other dogs, for example. This is one of the reasons why dogs smell urine.

The Jacobson's organ is dedicated exclusively to processing chemical messages by communicating directly with the dog's brain, so that no other scent can interfere with that process. This is a perfect and effective system for reading another dog's "I.D. card."

Why Do Dogs Sniff Each Other - How does your dog process all this information?

Do not prevent your dog from doing it!

It may be unpleasant or uncomfortable for you, but the fact is that it is a natural behavior and, therefore, should not be stopped. Although it may bother you, you should let your pet sniff other dogs for a few seconds so they can develop their chemical communication at ease.

And if you want to learn other fun facts about the behaviour of your dog, we invite you to read our other articles:

If you want to read similar articles to Why Do Dogs Sniff Each Other, we recommend you visit our Pets category.

Write a comment
What did you think of this article?
1 comment
reza Heydari
Where is this research?
which university?
1 of 3
Why Do Dogs Sniff Each Other