What makes a dog obsessed with sniffing certain people and not others?

What makes a dog obsessed with sniffing certain people and not others?

While our most widely used and strongest natural sense is sight, for dogs, their sense of smell is much more acute and informative than their eyesight, and dogs navigate the world by means of smell. The olfactory senses of dogs are continually bombarded by stimulus, much of which we as humans cannot even smell at all, let alone identify-and this sensitive canine sense of smell allows dogs to learn and identify things about their environment and the people and other animals in it that we have no clue about.

While all dogs have very acute olfactory senses, some breeds excel even compared to other dogs-like the bloodhound, the undisputed champion of the canine scenting world.

Dogs sniff everything as they walk along, and sniffing is a part of the greeting and introduction rituals between dogs and other dogs, and dogs and people too. It is a very unusual dog that will not sniff at someone when they first meet them, or when someone they know comes back home after being out-but some people seem to hold an abject fascination for dogs, and seem to be targeted by much more sniffing than others!

If you have ever wondered why your dog singles out certain people for much more sniffing than others, or if you have one friend that your dog seems obsessed about smelling, this can be very confusing-and you may never know for certain what the cause is.

However, learning to understand what dogs can pick up by means of scent, the types of scents that hold their attention and how dogs use scent for context can help when it comes to working out why your dog can’t seem to remove their nose from someone’s leg! Read on to learn more.

Dogs and scent

All dog owners know that the dog’s sense of smell is vastly superior to ours-dogs can detect scents over greater distances and in adverse conditions, as well as being able to pick up tiny amounts of a scent and determine different scents from each other, or break down a scent compound into individually identifiable parts.

They also retain excellent scent-based memories, and their brains form vast encyclopaedias of scent information and prior references, which help to provide context and associations for the dog’s life.

Scents that are appealing, repellent, unusual or new will all catch and hold your dog’s attention-and so if they are obsessed with sniffing someone, one or more of these factors is usually in play.

Here’s what your dog might be smelling that keeps them enthralled.


Ate something on the quiet? Your dog knows. Not only can your dog smell the smallest particles of dropped food that might have landed on your top without leaving a mark, they can even smell foods on your breath, even if these are undetectable to other people.

If someone has recently eaten, been cooking or works in a food service or manufacture environment, this might be all it takes to make your dog obsessed with the smell!

Other dogs

The scent of other dogs is always fascinating and important to our canine companions, and so if your friend has dogs of their own or even stopped to pat another dog on the way to meet you, your dog is likely to sniff around a lot to find out more about these dogs-so you might see that your friend with a dog of their own is the target of a lot of sniffing!

Other animals

Dogs will also be very keen to identify scent information on other animals too, such as pets like cats and smaller caged animals, and even wildlife. Your visitor might have picked up the scent of a fox or other wild animal on their shoes while outside-and your dog will want to know all about it!

Body smells

Even when you’re fresh out of the shower, you still smell-which doesn’t mean that you smell bad, but that you will still be giving off a distinct scent signature that the sensitive nose of the dog can pick up on-a combination of body scent, and that of the products you used to wash.

Dogs are fascinated by the smell of skin, sweat and bodily secretions, and if they find that someone’s individual sent is particularly new or appealing, they will make a beeline for them.

Additionally, what people eat can affect the way that they smell on a canine level too-so if you have friends from another culture or that eat a very different diet than you, this will smell unique to your dog.

Odd or unusual smells

If you have returned home from somewhere your dog has never been to or have been out somewhere where you will have picked up a lot of scents, like a busy city, your dog will find this fascinating too, and keep sniffing until they have identified as much information about it all as possible.


Yes, dogs can smell fear-the minute changes in the body’s adrenaline levels that precede heightened alertness and the fight or flight response. If you are talking to someone that is nervous or scared of dogs-or otherwise upset or frightened-their scent signature will be unique and lead to a lot of sniffing-as well as changing the way that your dog interacts with the person in question.

Hormonal changes

Dogs can smell hormonal changes that occur in both men and women, as well as pheromones and other chemical signatures that humans are totally unaware of. If you’re taking to someone and are not sure if they’re attracted to you or flirting with you or not, check out your dog’s behaviour-they know!


If you are ill, even with a minor ailment, this changes the way your scent signature smells to dogs, and dogs will know (often before you do) if you are sick or coming down with something.

In fact, the ability of dogs to detect minute changes in the body chemistry that indicate ill health, abnormalities or disease can be very useful-dogs can be trained to detect the onset of ketosis in diabetic people, and even used to sniff out cancer!



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