Do Dogs Recognise By Sight Or Smell?

Do dogs recognise by sight or smell? along with a picture of dog with closed eyes and head up.


Evolution over the years has enabled our furry friends to gain nearly unbeatable olfactory senses, but does this beat their own eyesight?

 There are so many famous occasions where a dog’s sense of smell has dictated its every move. For example, that viral video of a dog who didn’t recognise his previously hospitalised owner until the second he got a close-up sniff; then it was all wagging tails and happy days.

 However, there are other instances where you’d believe a dog relies on their sight more than their snout. For instance, when your dog stares you down when you enter a room or locks eye-contact from across the field.

 So, these questions really stand out: how do dogs know their owners? Do they simply recognise by sight or smell? And what is it about a dog’s smell that is so particular?


  1. Dogs and Their Eyes Vs Their Snouts

 As you may have guessed, there’s actually a large debate behind this. However, more and more science and research back the fact that dogs use their olfactory (nasal) senses to detect things that don’t even have an odour.

 As well as this, their eyesight is compromised due to the decreased colour spectrum. For example, us humans can see the RGB (red, green, blue) spectrum of colour while our four-legged friends can only see YB (yellow, blue). So, really, playing fetch with a red ball when our pups can’t see it proves they rely on their sense of smell.

 It’s this extraordinary sense of smell that helps them to decipher things like, where home is, if a female dog is in heat, what other dogs live in an area, if they feel comfortable, if people around them are feeling anxious and so much more.


  1. The Science Behind a Dog’s Sense of Smell

 With 220 million olfactory receptors, a dog’s sense of smell is said to be around 10,000 times better than our own and for good reason. For one, you may have noticed your dog being able to sniff the air and follow the scent; this is because dogs can move their nostrils independently and sense the direction of the source.

 When a dog breathes, around 12% of the intake is separated by a special flap to go into a ‘smelling chamber’. Here, the air enters hundreds of small sacks in the chamber that sieve the molecules to understand the chemical make-up at a very high-level.

 As well as this, there is an additional organ at the roof of the mouth close to the opening of the nasal cavity. This is called the Jacobsen’s organ. It connects to the brain in such a way that it doesn’t require the ability to ‘smell’ but more the ability to ‘detect’ things in the air. Much like how an insect can’t smell but can detect.

 It’s also one of the reasons you’ll see dogs panting through their mouths: to be able to smell better. Although, this organ is typically only associated with mating as it is used to detect pheromones that indicate when a female is ready to bring us some puppies. P.S., it’s also the sense that tells dogs whether you’re feeling anxious or not due to your adrenaline levels, so there’s no hiding that!


  1. Is it Possible to Know How Far a Can Dog Smell?

 The answer to this question has only been identified within recent years by researchers and scientists in university who have been able to study dogs and their response to certain smells.

 For example, the University of Adelaide found that a dog’s ability to smell near and far depends on a range of conditions such as the age of the dog, the dog’s wellness, the breed of the dog, the smell in question and even the wind direction.

 However, they did find that – under the perfect conditions – dogs were able to smell up to 20km away. There’s also studies that have suggested they can smell 40 feet ahead when it comes to being underground.

 Another factor that would help this range of how far a dog can smell as well as answering the question “how do dogs know when their owners are coming home?” is the nose wetness.

 You may have yourself wondering things like, “Why does my dog have a wet nose?” which is perfectly normal. Our pups have another evolutionary trait that helps them to keep their small snouts wet. This is because moisture helps to capture scent particles and, the more a scent a dog can smell, the more they can detect whether or not you’ll be heading through the door shortly.

  Also, have a look at Why Does Your Cat Have a Flabby Belly?

  1. How Do Dogs Know Their Owners?

 Despite the viral video that went around suggesting dogs can’t tell if their owner is there without a good sniff, they do use their eyes to recognise.

 However, it is still their sense of smell that helps them determine who’s who and to feel relaxed.

 It is believed that the answer to the question “how do dogs know their owners?” is entirely down to a Pavlov’s ritual. Where associations between the owner and stress-relief, food, drink, treats, fun, games, home, relaxation and all the other good things in life are made.

 Then, there’s the whole notion of a dog being able to remember a smell forever. While that can be a curse depending on the smell, it can be a blessing when remembering their owners after a brief separation period. Especially when you see the tail wagging, tongue-out panting and paws pounding towards you ready for a lick.


  1. How Do Dogs Know Their Owners Are Coming Home?

If you’ve ever noticed your fluffy partner in crime already waiting at the door for you to walk in from school or work, it’s likely you’ve wondered why.

In fact, so have many. There have been studies that have only raised a few explanations such as:

  • Smelling their owner come home when nearby
  • Hearing their owner come home when nearby
  • Adopting routine times of return
  • Looking at social cues out of the window or in the house when others are home
  • Selective memory of the owner

 However, even a 1994 experiment by author Rupert Sheldrake saw a pup go to the window to await the return of their owner when the owner decided to come home. It didn’t matter where the owner was, when or how they decided to come home, it was almost like a sixth sense!

 Despite this, we know that perfect conditions can give a dog a smelling range of up to 20km with the ability to smell more than we could ever imagine. So, maybe it is less of a sixth sense and more one of the original five: smell.

That brings a close to the wonderful world of wagging tails and their olfactory senses. Here at Hiputee, we love to bring you interesting nuggets of information that pulls you closer to your furry friend at home.