Why is my dog's nose running?
A runny nose in dogs is usually nothing serious and often clears up on its own, most commonly caused by irritation, a mild upper respiratory infection, or something as simple as excitement or cold air. Ring your vet if the discharge is thick, coloured, or one-sided, or if your dog seems unwell in any other way.
Usually not urgent
This is common and often manageable at home — but see a vet if it persists, gets worse, or comes with other changes.
What a normal, minor runny nose looks like
A clear, watery discharge from both nostrils, especially after a walk in cold weather or a bout of excited sniffing, is common and rarely worth worrying about. Dogs' noses are also simply wetter and more active than a person's, and some produce more visible discharge than others as part of their normal range. A dog who has just been sniffing intently at something on a walk will often have a slightly runnier nose for a short while afterwards, purely from the effort of it.
What matters more than the discharge itself is whether your dog is otherwise their normal self — eating, playing, breathing normally, and not pawing at their face or sneezing excessively. A minor, short-lived runny nose in a bright, well dog is a very different picture from one that lingers or worsens. Keeping a rough note of when it started and whether it is improving or not gives you something concrete to describe if it does not settle.
Common causes
Irritants such as dust, pollen, strong household sprays or smoke can trigger a temporary runny nose in an otherwise healthy dog, in much the same way they might irritate a person's nose. Mild upper respiratory infections, sometimes grouped loosely as kennel cough, can also cause nasal discharge alongside other symptoms like coughing. Seasonal changes are worth noticing too, since some dogs react more to pollen at particular times of year in a pattern that repeats annually.
A foreign object such as a grass seed or blade of grass lodged in the nostril is a more specific cause worth considering, particularly if the discharge is from one nostril only, comes on suddenly, and is accompanied by sneezing or pawing at the nose. Dental problems, particularly with the upper teeth, can also occasionally show up as nasal discharge on the affected side, since the roots of the upper teeth sit close to the nasal passages. Breeds with short, flat faces can also be more prone to nasal discharge generally, simply because of how their airways are shaped.
When it is worth seeing a vet
Ring your vet if the discharge is thick, yellow, green, or contains blood, if it is coming from one nostril only, or if it has lasted more than a few days without improving. Sudden onset alongside sneezing, pawing at the face, or an obvious foreign object are also worth getting checked promptly rather than waiting.
A runny nose alongside other symptoms — coughing, lethargy, reduced appetite, or laboured breathing — should always be treated as the more significant picture rather than the nose alone, and is worth a vet visit regardless of how minor the discharge itself looks. Older dogs and dogs with a known dental history are worth watching a little more closely, since both are more likely to have an underlying cause behind a persistent discharge.
What can help at home in the meantime
For a mild, short-lived case with no other symptoms, gently wiping away discharge with a damp cloth keeps your dog comfortable while it settles on its own. Avoiding known irritants — strong cleaning sprays, dusty bedding, smoke — is a sensible precaution if you suspect one might be the cause. Washing bedding regularly and airing rooms after cleaning are small, low-effort habits that reduce ongoing exposure to the sort of household irritants that commonly set this off.
General coat and skin wellbeing supplements are sometimes part of a dog's broader routine, but they are not a treatment for a runny nose and should never replace a vet visit if the discharge does not settle or other symptoms appear.
What can help
Things we stock that owners commonly use alongside a vet’s advice — not a substitute for it.
Leucillin Antiseptic Skincare Spray for Cats & Dogs
A versatile, alcohol-free antiseptic spray that cleans, soothes, and helps protect your pet's skin from bacteria, viruses, and fungi.
From£16.49
Absorbent Cotton Gauze Swabs for Pets – Pack of 100
Highly absorbent, low-lint cotton gauze swabs produced in clean conditions — a practical first-aid essential available in three size and ply combinations.
From£4.49
MPS Medical PetS Boot – Waterproof Paw Protector
A vet-recommended waterproof boot that keeps bandages, dressings, and casts dry during walks and wet weather.
£30.49
Common questions
- Is a runny nose always a sign of illness in dogs?
- No, a clear, watery discharge from both nostrils is often just irritation, cold air, or excitement, and settles on its own in an otherwise well dog. It becomes more of a concern if it is thick, coloured, one-sided, or accompanied by other symptoms.
- Why is my dog's nose running from one side only?
- Discharge from a single nostril is more likely to point to a specific, localised cause, such as a foreign object like a grass seed, or a dental issue affecting the teeth on that side. This pattern is worth getting checked by your vet rather than waiting to see.
- Can allergies cause a runny nose in dogs?
- Yes, environmental irritants and allergens can trigger nasal discharge in some dogs, similar to how they might affect a person. If this happens repeatedly around the same triggers, it is worth mentioning to your vet, who can advise on managing it.
- Should I worry if my dog is also sneezing?
- Occasional sneezing alongside a runny nose is often part of the same mild irritation and nothing to worry about on its own. Frequent, sudden sneezing, especially paired with pawing at the nose, is more suggestive of something lodged in the nostril and is worth a vet check.
- Can a cold spell make my dog's nose run more?
- Yes, cold air alone can cause a temporary clear discharge in many dogs, similar to how a person's nose might run outdoors in winter. This is normal and settles once your dog has warmed up again, without needing any treatment.
Related
Sources
Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.
Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.