If your dog is constantly sneezing and has a runny nose, it can be frustrating trying to determine the cause. There are many potential causes of a runny nose in dogs, some of which are relatively benign and easily treated, while others may be indicative of a more serious problem. In this article, we will discuss the most common causes of a runny nose in dogs, as well as how to treat them.

What is a runny nose in dogs and what are the most common causes?

A runny nose in dogs is a condition in which the dog's nose secretes an excessive amount of discharge. With a runny nose in dogs, there are a few types of discharge you may notice. The most common is a clear, water-like discharge, cloudy mucoid discharge, or a thick greenish discharge. Each of these can be important when it comes to the severity and cause of a runny nose in dogs. Additionally, the discharge can be unilateral (one-sided), or bilateral which means both sides (both nostrils).

Common causes of a runny nose in dogs include:

  • Idiopathic - typically seen as a clear, bilateral nasal discharge without any other symptoms present. This is not a cause for concern and is self-limiting in most cases.
  • Allergies - will commonly cause a clear to cloudy, bilateral nasal discharge. Other symptoms such as sneezing or skin itchiness are other symptoms that may be noticed with allergies.
  • Dental disease - typically seen as a mucoid, unilateral or bilateral nasal discharge. Bad breath (halitosis) is often also noted with dental disease.
  • Foreign Object - commonly seen as a unilateral (one-sided) that is greenish or mucoid in consistency. A foreign object can be something as simple as grass awn or as large a piece of a stick
  • Fungal infection - typically seen as a clear to cloudy, mucoid, unilateral or bilateral nasal discharge. Other symptoms such as sneezing, fever, and lethargy may also be noted with a fungal infection.
  • Neoplasia or cancer - typically causes unilateral (one-sided), thick green mucoid discharge. Other symptoms such as weight loss, lethargy, and anorexia may also be noted with cancer.

How can you tell if your dog's runny nose is serious or not?

In general, a runny nose in dogs with a clear discharge is not a serious condition and can be easily monitored at home. However, there are a few cases where you should be concerned and seek veterinary care.

You should contact your veterinarian if you notice any one of the following symptoms:

  • Unilateral (one-sided) nasal discharge
  • Green or blood-tinged nasal discharge, affecting one nostril or both
  • Accompanying symptoms of a runny nose in dogs such as coughing, lethargy or anorexia (loss of appetite)
  • Loss of airflow through the nostrils which can be identified with excessive panting or difficulty breathing. Stertor may also be noticed which is an abnormal noise heard during inspiration.

How is the cause of a runny nose in dogs diagnosed?

Your veterinarian will start with a detailed physical examination of your dog. They should be able to assess the type of discharge, which nostrils are affected, and if there are any other symptoms present such as facial asymmetry, evidence of pain and lymph node enlargement. Additionally, a thorough oral examination will be performed to look for any dental disease that may be causing the runny nose.

In some cases, your veterinarian may recommend additional testing such as:

Radiographs (X-rays) - to look for foreign bodies or masses in the nasal cavity

Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) - to further evaluate the nasal cavity for masses, foreign bodies, or other abnormalities

Nasal swabs - to collect a sample of the discharge for analysis and evaluate the types of cells that may be present

Rhinoscopy - a procedure in which a small camera is used to visualize the inside of the nasal cavity.

Treatment of a runny nose in dogs

The treatment for a runny nose in dogs will vary depending on the underlying cause.

For idiopathic runny noses, no treatment is typically necessary as they are self-limiting and will resolve on their own. Allergies can be treated with antihistamines, corticosteroids, or immunotherapy. Dental disease will require a complete dental cleaning under anesthesia along with possible extractions. If a foreign body is present, it will need to be removed under anesthesia. Fungal infections are treated with oral anti-fungal medications. Cancer will require referral to a veterinary oncologist for further treatment options which may include surgery, radiation therapy, or chemotherapy.

In some instances, the underlying cause of the nasal discharge will result in secondary bacterial infection. Therefore, your veterinarian may prescribe antibiotics to address the secondary infection. A runny nose in dogs is rarely only caused by a bacterial infection.

What is the prognosis for a runny nose in dogs?

The outlook for the condition depends on what is causing it and how well it can be treated.

If a foreign body is removed from a dog, the prognosis is good. However, if the dog has cancerous growths in its nose, the prognosis is poor.

For dogs that have an infection of the upper respiratory system, if they experience damage to their turbinates (a type of nasal bone) or epithelium (the outermost layer of cells), then this often becomes a chronic condition that may be manageable but never cured.

A runny nose in dogs can be caused by a variety of things, such as dental disease, allergies, fungal infections, foreign material, cancer and idiopathic causes. If your dog is experiencing a runny nose, it's important to take them to your veterinarian so that the cause can be diagnosed and treated. Some symptoms that you should look out for include unilateral discharge, green or blood-tinged discharge, facial asymmetry, difficulty breathing, and loss of airflow. Mild cases with a clear discharge often require no treatment, while more severe cases may require medications or other surgical treatments. If you have further questions about nasal discharge in dogs, please contact your veterinarian.