Why is my dogs nose running?

As a dog lover, a wet nose can catch your attention immediately: a new puppy sneezing at home, a recent shelter intake with a damp snout, or a row of dogs boarding after a weekend at the kennel. Those moments are when curiosity becomes care — and knowing what to watch for can help you decide whether to relax, manage at home, or call the vet.

When to act — a dog-lover’s guide to recognizing concern

There are a few everyday situations that make a runny nose worth paying attention to. A newly adopted puppy whose nasal discharge starts the first day or two after arrival may need a check to rule out contagious infections; shelter staff and foster volunteers often monitor for this closely. Breeders may notice nasal fluid as an early sign that a litter member is exposed to an upper respiratory bug. Walkers and groomers who see one-sided discharge after a walk or bath may be looking at a foreign material lodged in the nostril. If multiple dogs in a kennel or dog park develop similar symptoms, that clustering increases the chance of an infectious cause.

People who benefit from reading this include pet owners who want to make good first decisions, breeders and rescue staff who must manage groups of dogs, dog walkers and groomers who are often the first to see symptoms, and trainers who might need to modify routines for an affected animal. A quick mental checklist that helps me triage is simple: how long has the discharge been present, what color and consistency is it, and has the dog’s breathing or behavior changed? Those three observations often point toward either a watch-and-wait approach or the need for veterinary care.

What’s probably causing it — allergies, infections and other common culprits

• Clear, watery discharge is commonly normal nasal secretion or allergy-related and may not need urgent treatment.
• Thick, colored (yellow or green) discharge is more likely linked to a bacterial or viral infection or sinus inflammation and may require veterinary assessment.
• One-sided discharge, foul smell, or blood may suggest a lodged foreign object, dental disease affecting the nasal cavity, or rarely a growth that needs prompt attention.

How your dog’s nose works and what its discharge can mean

A dog’s nose is doing several useful jobs at once. The thin layer of mucus across the nasal lining helps humidify incoming air so the lungs stay comfortable and also traps dust, pollen, and tiny particles before they reach sensitive tissues. That mucus is also where odor molecules dissolve so the olfactory cells can detect them; a slightly tacky, moist surface actually improves a dog’s ability to smell.

The nasal passages are not passive tubes; they have glands that produce mucus and immune tissue that samples what comes in. That immune activity is helpful — it may cause a bit more fluid production when the nose encounters irritants or microbes — but it can also be the reason discharge changes color or thickens. For that reason, an increase in nasal wetness can be an appropriate, protective response rather than a problem by itself.

When a runny nose is normal — and when it signals trouble

There are many non-threatening reasons a dog’s nose may run more than usual. Seasonal allergens such as pollen and mold are common culprits, especially in dogs who sniff a lot during walks through grassy or wooded areas. I often see clear, watery drips in dogs with atopic tendencies after long springtime outings. Cold air and rapid changes in humidity can increase visible nasal secretions because the air is drier or because the nose produces extra moisture to compensate.

I also see runny noses triggered by environmental irritants: tobacco smoke, strong household cleaners, air fresheners, or grooming products with heavy scents. Dogs in crowded kennels or at dog parks face higher exposure to respiratory viruses and bacteria, so an isolated watery nose in a single dog is different from multiple dogs with similar symptoms. Finally, behaviors such as vigorous sniffing and digging can push pollen and fine debris into a nostril and cause localized irritation and increased discharge.

Don’t ignore these signs: red flags that need veterinary attention

Some patterns tell me that a visit to a veterinarian should not be postponed. Thick yellow or green discharge that looks pus-like may suggest a bacterial infection or secondary inflammation and often merits professional evaluation. Blood in the discharge or a persistent one-sided flow can be associated with a foreign body stuck in the nostril, dental infections that extend into the nasal cavity, or, less commonly, a mass. Facial swelling on one side, reluctance to eat, high fever, pronounced lethargy, or labored breathing are all signs that the dog needs urgent veterinary attention rather than home care.

If a dog starts sneezing frequently with a strong, unpleasant odor from the nose, that smell may indicate infection or tissue breakdown inside the nasal passages and should be checked sooner rather than later. Puppies, elderly dogs, or dogs with known immune problems should be evaluated more readily because they can deteriorate faster when infections are present.

What to do right away: safe immediate steps for owners

The first useful step is careful observation. Note how long the nose has been runny, whether the discharge is coming from one nostril or both, the color and thickness, and whether there is any smell. Photographing the discharge and the dog’s face can help you and your veterinarian track changes over time. Gently wiping the nose with a soft, absorbent cloth or an unscented pet wipe removes surface crud; avoid pushing into the nostril or probing blindly.

Avoid giving human cold medicines or antibiotics without veterinary guidance — some common human drugs are unsafe for dogs or mask symptoms that help a clinician diagnose the problem. If you see the red-flag signs mentioned above, or if colored discharge or other concerning symptoms persist longer than 48–72 hours, call your veterinarian. If you suspect the discharge could be infectious and you care for other dogs, keep the affected dog separate until you know more to reduce the chance of spread.

At-home care and simple training to help manage nasal discharge

Many preventative steps reduce the frequency of irritating runny noses. Minimize indoor irritants by using pet-safe cleaning products and avoiding smoking inside the house. If your home is very dry in winter, a humidifier may reduce crusting and irritation in the nose; conversely, if your home is very humid and promotes mold, a dehumidifier may help. Keep grooming products unscented and avoid using strong perfumes around dogs who seem sensitive.

Training and supervision are practical defenses. Teach a reliable “leave it” cue so a dog does not pick up or sniff dangerous items on walks. Supervise foraging behavior and discourage nosing into piles of leaves, compost, or trash where plant matter or tiny foreign objects can become lodged in a nostril. Maintain routine veterinary care — vaccinations, parasite control, and dental exams — because good baseline health reduces the risk of secondary nasal problems and makes any new issue easier to diagnose and treat.

Practical gear and supplies worth keeping on hand

• Soft, absorbent cloths or unscented pet wipes for gentle cleaning of the nose and face.
• Vet-approved saline nasal spray or rinse for short-term use when advised by your veterinarian; never use human medicated sprays without guidance.
• A basic humidifier for dry climates (or a dehumidifier for overly damp homes) to stabilize indoor air and reduce mucosal irritation.
• Your phone or a small camera to document the discharge and any facial swelling over time, which helps your vet assess progression.

References and expert sources

• AVMA: “Kennel Cough (Canine Infectious Tracheobronchitis)” guidance and resources for contagious respiratory disease management.
• Merck Veterinary Manual: “Nasal Disease in Dogs” — overview of causes, diagnosis, and treatment approaches.
• Merck Veterinary Manual: “Canine Infectious Tracheobronchitis (Kennel Cough)” for causes, clinical signs, and prevention strategies.
• Journal of Veterinary Internal Medicine: articles on chronic rhinitis and nasal disease in dogs for diagnostic considerations (search specific reviews on canine rhinitis).
• American College of Veterinary Internal Medicine (ACVIM) consensus statements and board-certified veterinary ENT specialists for advanced diagnostic and therapeutic options.