In Why Are Dogs Noses Wet, we celebrate dogs’ incredible noses, and marvel at their sense of smell.
Sarah Holloway makes sure you have all the information you need to know when your dog’s nose is healthy, and when it needs some extra care.
Know your dog’s nose!
Their noses, and the areas of their brain dedicated to making sense of smells, are highly specialized.
Perhaps because their sense of smell is one of the first things we associate with dogs, it’s easy to picture their noses.
When my little girl asks me to draw animals for her – alas not a talent I am particularly blessed with – the distinguishing characteristic of dogs is usually their nose: an upside down trapezium with curved corners.
I flatter myself that it gives their likenesses a lovely friendly and trustworthy appearance.
What makes a dog’s nose so special?
If you’ve ever had a chance to examine a dog’s nose up close, you’ll have noticed it’s curious lumpy surface. That surface has a special name: the rhinarium.
Just like humans, dogs have specialized nerve endings in their nose (scent receptors) which detect smells and send information about them back to the brain.
Unlike humans, those scent receptors aren’t just inside the nose, they’re all over the surface of the rhinarium too.
All those tiny little lumps are there to increase it’s surface area, so that there’s room for as many scent receptors as possible.
Canine expert Professor Stanley Coren writes that the surface area of the human nose covered by scent receptors is just one square inch, but a dog’s can be over sixty times bigger – the size of a piece of letter paper!
With that much surface area, a dog nose can have as many as 300 million scent receptors, depending on the breed of dog.
To give you another comparison, humans have just 5 million scent receptors.
But the number of scent receptors isn’t the only special physical adaptation dogs have.
Like a lot of other animals (but not us humans), dogs have a vomeronasal organ right at the back of their nose, which detects scents in fluids.
By contrast we can only detect the smell of particles which have become airborne.
Dogs can even move their nostrils independently to pinpoint the exact location of a smell, and when they sniff they can accumulate new air with each sniff without exhaling all of the scent from the previous breath.
Their noses really are incredible!
The power of the dog nose
Those remarkable nasal refinements mean dogs have a sense of smell at least 100 times better than humans.
And boy do they rely on it – up to 30% of their brain is thought to be used for interpreting smells, 40 times more brain space than we use.
When dogs meet another dog they can tell if they are a boy or a girl, where they’ve been and who they’ve met, what mood they’re in, and even what they had for breakfast.
And because dogs can detect scents in tiny concentrations far beyond our own sense of smell, they can be trained to help us in the most incredible ways.
Medical companion dogs can tell when someone is going to have an epileptic seizure or recognize the onset of sudden hyperglycemia in people with diabetes.
Why do dogs have wet noses?
If you’ve ever had a nose shoved into your hand by a dog keen to make your acquaintance and learn everything about you (like “have you brought snacks?”), you might have been left slightly soggier for the experience.
Dogs wet their noses by secreting mucus from the their nostrils and giving it the occasional lick.
They also have an impressive knack for finding wetness in the environment: in their water bowl or even a patch of dewy grass.
Having a wet nose serves two special purposes for dogs.
First, just like the mucus in our own nose, it traps particles of scent against the skin to make it easier for the scent receptors to register them.
Secondly, because movement in the air evaporates the wetness and cools the skin, dogs can use that information tell which direction a scent is coming from.
What does it mean when a dog’s nose is dry?
There’s an old wives’ tale that if your dog’s nose is dry, they are sick.
But in fact that’s just not the case.
It’s completely normal for your Labrador’s nose to be wetter at some times than others.
And there’s plenty of variation between individuals as well. Some dogs just have drier noses than others.
Because of this natural variation, a dry dog nose doesn’t mean your pet is sick.
On Web MD, Professor Steven Marks at North Carolina State University’s College of Veterinary Medicine says
“In a very dehydrated dog, yes, the nose might be dry. But dogs can have moist noses because they’re healthy, and they can have moist noses when they have a nasal disease. It’s just not a reliable sign”.
Should a dog’s nose be cold?
Again, there’s no right or wrong answer to this questions.
Having a cold nose is really a side-effect of keeping it wet.
When dogs wet their nose to help locate the source of a smell, they rely on evaporation to tell which way the air is moving.
Dampness evaporating from skin also cools it down – that’s exactly the principle behind why we sweat – so feeling cool to the touch is just a natural side effect of keeping it wet enough to do it’s job.
My dog’s nose is warm!
That’s fine! It’s completely normal for the temperature and dampness of your dogs nose to change throughout the day, and vary between individuals.
Even if you’re used to it being cold and wet, don’t be alarmed if it is occasionally warm.
Dog dry nose treatments
A dry nose in and of itself isn’t a problem and doesn’t require treatment.
If your dog’s nose does seem a little drier than usual (perhaps because you’ve turned the central heating on at home), there are plenty of natural products on the market which work like lip balm for humans.
For example this snout soother for dogs by the Natural Dog Company.
Don’t use paraffin-based products like Vaseline, they only give the illusion of relief, whilst actually drying the skin out more.
And never use medicated products unless advised by your vet to do so.
Whilst a dry nose isn’t necessarily a sign that your dog or their nose is unhealthy, there are some ways that your dogs nose can tell you it’s time for a check up with the vet. We’ll look at those now.
Nose problems: my dog’s nose is running
As we discovered earlier, dogs secrete mucus from their nostrils to keep the rhinarium wet and improve their sense of smell.
However, a trip to the vet is in order if the discharge becomes cloudy, yellow, green, or smelly.
A runny nose which is cloudy, yellow, green or smelly could be a sign of allergy, blockage, infection, or sign of some thing more unusual.
Whatever it is, your vet is the best person to identify it and prescribe a course of treatment.
Nose problems: skin diseases
Skin diseases on the snout or rhinarium of dogs can be caused by all kinds of things, from easily managed mites and fungal infections to more sinister immune system disorders and cancers.
Symptoms to look out for include:
- Ulcers or nodules on or around the nose
- Hair loss on the bridge of the nose
- Sores or wounds with pus coming from them
- Loss of pigment or excess pigment
- Redness of skin – we assume a red nosed human just has a cold, but a red nose dog should see a vet
If you notice any of these symptoms on or around your dogs nose, take them to your vet for a thorough examination. Your vet may need to carry out some tests in order to make a diagnosis.
Nose problems: nose bleeds
Nose bleeds in dogs are usually the result of a scratch, a bump or an upper respiratory tract infection.
If your dog’s nose is bleeding, stay calm and place an icepack over the bridge of their nose.
I know that remaining calm is easier said than done when you’re worried for your Lab, and especially if you’re squeamish around blood.
But if your dog picks up on your anxiety and becomes agitated in turn, the increase in blood pressure will make the bleeding worse.
An ice pack will constrict the blood vessels in the nose and slow the blood loss. Take extra care applying an icepack to the face of a flat-nosed dogs.
If a nose bleed doesn’t stop, or your dog gets recurring nosebleeds, ask their vet for advice.
In the know about dog noses
So why are dogs noses wet? Well, dogs have wet noses to improve their sense of smell.
But a dry nose dog or a runny nose dog isn’t usually any cause for concern, just as a wet nose dog doesn’t guarantee they are healthy.
It’s worth getting to know your dog’s nose, so that you can recognize any changes in it’s appearance that might need veterinary attention.
Which isn’t really such a chore, when their noses are so lovely!
Tell us about your dog’s nose!
Does your dog greet you with a cold wet nose, or a warm dry nose? Have they ever left you completely flabbergasted by their acute sense of smell?
Tell us your stories in the comments section below.
Case, L., (2013), The Dog: It’s Behaviour, Nutrition, and Health, 2nd Edition, John Wiley & Sons.
Coren, S. & Hodgson, S., “Understanding a dog’s sense of smell”, www.dummies.com.
Davis., S., (2012), “Is a Dog’s Hot Nose a Sign of Illness?”, Web MD, www.pets.webmd.com.
“Diseases of the Skin on the Nose in Dogs”, Pet MD, www.petmd.com.
“Dog Sense of Smell”, Animal Planet, www.animalplanet.com.
“Nosebleeds or Epistaxis in Dogs”, VCA Animal Hospitals, www.vcahospitals.com