Understanding dog behaviour

Why do Dogs Sniff Urine?

Max. D Gray
By Max. D Gray. Updated: January 16, 2017
Why do Dogs Sniff Urine?

When you've walked your dog, you've no doubt noticed how they sniff other dogs' urine. Sometimes they even smell their own urine. Why do they do this? These animals sense of smell is their most developed sense. It is a clear indicator of dogs that have previously passed by a place and wanted to mark their territory whilst giving valuable information about themselves, such as if they are male or female, if they have a dominant or pleasant attitude, etc. This OneHowTo article explains why dogs sniff urine so you can better understand the behaviour of your dog.

You may also be interested in: Why Do Dogs Sniff Each Other

Steps to follow:


First, you should know that dogs urinate for two reasons: to empty their bladder or to mark their territory. There are many ways of making these markings but urinating is one of the most common ways of dogs indicating they have been there and alerting others of their presence.

You can differentiate between the types of your dog's urination if you look at the amount of urine they expel. If they merely squirt a small amount, it is because they are marking their territory and they just want to leave a trace of their smell. However, if they urinate for 15 or 20 seconds instead, they are getting rid of excess liquid without the sole intention of marking.

Why do Dogs Sniff Urine? - Step 1

Dogs mark their trail with urine as they have a much more developed sense of smell than humans. With a simple scent they can detect very diverse information about an animal that has urinated such as a dog's age, sex, attitude, etc. To give you an idea of dogs' great sense of smell, here is some relevant data:

  • Their sense of smell is 1,000 times more developed than that of humans.
  • They have 200 million olfactory receptors in their noses whilst humans only have 5 million.
  • The nerves which come from the sense of smell reach over 100 cm2 in dogs' bodies, whilst they only extend to 10 cm2 in humans.

This is one of the key factors that can help with understanding why dogs sniff urine.

Why do Dogs Sniff Urine? - Step 2

Now you understand this great canine ability, it is easier to understand why they want to sniff urine. Doing this, they can determine information about another dog who has left their mark.

Remember that dogs mark their territory and smell another animal via pee and faeces. So when they receive information about which dog owns that space and has since left, a dog who most recently urinates in that space is then indicating they now own that space. For this reason, if animals smell the urine of another dog, chances are they will also leave their mark to claim the area.

What's more, if you always walk through the same area, it is also common for your dog to always pee in the same places to strengthen their presence and tell others that it's their space.

Why do Dogs Sniff Urine? - Step 3

What information does a dog's urine give?

  • How many dogs are in an area: By being able to distinguish the different traces of dogs, your animal will know how many have been there and therefore how many there are in total.
  • How much time has passed: The smell also allows them to determine the time that has passed since another dog has been there and they therefore know who was the last to mark the territory. It is most common for them to also make their mark to become the owners of the space.
  • If there are females in heat: Urine is a clear indicator of whether there are any female dogs in heat.

Also, if you've ever seen your dog roll around in their own urine, this is because they want to emphasise their own smell so other animals can easily find them. This mainly occurs in wild animals or prey animals that usually cover large areas or forests where it may be easy to get lost.

Why do Dogs Sniff Urine? - Step 4

So when asking why dogs sniff urine, the answer is clear: to find out which dogs have been there and then specify their territory. But there's more, because many dogs roll around in another animal's pee or even in faeces. Although it may seem like a disgusting act, the truth is that this is their most natural instinct which originates from their distant relatives, wolves.

There are different reasons why a dog does this. One of them includes wanting to camouflage their scent so they are able to hunt. This is a natural instinct that they can't control, even though they don't use it. It is also possible that they do it to remove the smell of soaps or chemicals that they don't like. OneHowTo explains in detail why dogs roll in poop.

Why do Dogs Sniff Urine? - Step 5

They also lick other dogs pee, or even their own pee, which is another of their most common habits. There are different reasons which can prompt an animal to lick urine. Here you can discover the most common reasons:

  • To keep clean: If the animal is locked in a cage or spends many hours a day in a crate or a small room, it is normal for them to lick their own urine to keep their surroundings clean. If your dog has a tendency to urinate in the house, you can learn how to stop this behaviour in our article.
  • Due to thirst: Another reason may be that the animal feels like drinking and has been unable to find water at home, so they will go to a source of pee to quench their thirst. It is important that you always leave out a clean and fresh bowl of water for your animal to hydrate themselves.
  • Out of curiosity: It is also possible that they lick other dogs pee to receive information about another animal, which is another way of finding out who has been there.
  • To find a female in heat: Besides the smell, the taste of pee from females in heat also makes it likely that your animal will want to try it to get all the information.

If you want to read similar articles to Why do Dogs Sniff Urine?, we recommend you visit our Pets category.

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