Runny Nose in Dogs

Shawna Abrams, DVM, MPH

Shawna Abrams, DVM, MPH

Published Jun. 27, 2023

As with people, dogs can have an occasional runny nose, especially if they’re prone to seasonal allergies. A little bit of thin clear discharge once in a while may be normal, but if it’s an abnormal color (yellow, green, cloudy, or bloody) or there are other signs such as congestion, coughing, sneezing, a change in behavior, or trouble breathing, prompt medical attention is recommended.

In younger dogs, the underlying cause is more likely to be congenital (an underlying issue they were born with), infectious, or related to toxicity. With older dogs, the cause is more likely to be related to a dental issue, cancer, or systemic disease.

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What To Do if Your Dog Has a Runny Nose

As long as there’s a small amount of clear discharge without any additional signs, simply continue to monitor and watch for worsening signs. However, contact your veterinarian if you notice:

  • Congestion or labored breathing

  • Noisy breathing

  • Discolored nasal discharge (including blood)

  • Lethargy (abnormal tiredness)

  • Coughing, or coughing to the point of gagging

  • Eye discharge

  • Anorexia (reluctance to eat)

  • Any pain or swelling on the face or nose

If your dog is overheated there can be clear discharge coming from their nose. Unlike humans, who sweat through their skin, temperature regulation in dogs is through the pads of their feet and nose. If you notice clear discharge and your dog has recently been active or is out in warm temperatures, move them to a cool spot, preferably indoors, and be sure to provide water; if your dog continues to be exposed to heat, it could result in heatstroke, which is a medical emergency.

Causes of Runny Nose in Dogs

Nasal discharge is a relatively vague symptom that can encompass a wide range of causes. Working with your veterinarian to figure out the underlying cause is the best way to formulate a treatment plan. A runny nose in dogs could be caused by the following conditions:


In general, dogs can have allergies to fleas, a particular food, or allergens in the environment. A runny nose may indicate an environmental allergy; dogs can have seasonal allergies especially during the spring and fall as pollens, mold, and yeasts are increasing. It’s important to work with your veterinarian when allergies are suspected.


Cleft palate: The roof of a dog’s mouth is called the palate, and with a cleft palate, there’s an opening down the middle of the roof of the mouth. This opening allows communication between the nose and the mouth. Because a cleft palate can lead to serious medical problems, it’s important to contact your veterinarian if you suspect this condition.

Foreign body or trauma

Because dogs love to have their noses to the ground, they can inadvertently inhale things like blades of grass, seeds, or small pieces of wood. They can also accidentally bump into things and injure their noses.

Dental issues

  • Tooth root abscess

  • Oronasal fistula: an abnormal passageway, typically through the roof of the mouth into the nasal cavity, caused by a diseased upper tooth.


There are different types of nasal tumors in dogs, and swelling, deformity and irritation can cause nasal discharge. Specifically, adenocarcinomas are generally localized and develop from glands that produce mucus; because of the local aggressiveness of this type of cancer, there can be an incredible amount of damage to nasal tissue.


How Veterinarians Diagnose the Cause of Runny Nose in Dogs

Your vet will ask lots of questions to get a detailed history and perform a physical examination, focusing on listening to the heart and lungs and looking inside your pet’s nose and mouth.

If a viral infection is suspected, the history and examination may be enough for a diagnosis. However, your vet may ask to do a nasal swab cytology, which would involve using a swab to gently obtain some discharge to examine under a microscope.

A rhinoscopy (scope of inside of nose) is also done to look deeper inside the nose to see if a biopsy is needed.

If additional tests are needed, blood tests do not usually reveal the cause for nasal discharge. They may, however, show indications of other underlying systemic issues. X-rays or advanced imaging such as a CT scan may be required.

Treatment For Runny Nose in Dogs

Here are some ways you can help at home:

  • Until your dog is seen by a vet, continue monitoring them for worsening signs.

  • If your dog is not eating well, try warming up canned food so they can smell it better, making it more palatable.

  • If you’ve noticed some congestion, as long as your dog is otherwise acting normally you can try a humidifier to loosen any mucus.

After your pet has a diagnosis, treatments will vary depending upon the underlying cause.


If seasonal allergies are the offender, your veterinarian may offer supportive care or allergy medications, such as antihistamines or other prescription medications, to help ease the clinical signs.  


With any nasal tumor, your veterinarian will go through a series of diagnostics to determine the type of tumor, but also to determine if it has spread throughout the body. Once the tumor is staged (identifying the class and level of tumor), your vet will determine an overall treatment plan.

Cleft palate

Because of the opening in the palate that leads to the nose, food and water can get into the nose and cause a multitude of problems. Almost all cases of cleft palate require surgery to correct the abnormality and to help prevent additional and potentially fatal medical issues, such as aspiration pneumonia or infection.

Foreign body or trauma

If you know that your dog has something stuck in their nose, it’s important to seek medical attention immediately so it can be removed.

Dental Issues

If your vet suspects a dental issue, they will do dental X-rays to see the condition of the roots and bones. Your vet may prescribe antibiotics, pain medication, or extractions, then recommend a prescription diet.


Treating the cause of an underlying infectious illness is entirely dependent on the infectious agent. In the case of kennel cough or pneumonia, if a bacterial infection is involved, antibiotics are sometimes prescribed. In the case of fungal and parasitic infections, antifungal and antiparasitic medications are prescribed by your veterinarian.

Featured Image: Kravchenko


Brooks W. Kennel Cough in Dogs. Veterinary Partner, 2016.

‌Feldman E, Ettinger S. Textbook of Veterinary Internal Medicine. Vol 1. 6th ed. Elsevier Saunders; 207-210.


Shawna Abrams, DVM, MPH


Shawna Abrams, DVM, MPH

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