Nasal discharge in dogs

Discharges from the nose can be clear fluid, mucus, pus, blood or a mixture of substances. This discharge can come from the nose itself or from deeper in the respiratory tract, eg the lungs. There are many causes of nasal discharge, all of which require specific treatments, so it is important to get veterinary help as soon as you notice a problem. The outcome for your pet will depend on the cause and the extent of disease when treatment is sought.

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A nasal discharge means anything that runs out of your pet’s nose. Many discharges start as a clear fluid, looking like a runny nose. In most cases of infection, the discharge is thicker and green or yellow in color, a bloody discharge will be reddish and is often mixed with snot or fluid.

If a nasal discharge clogs up the air passages, you may notice increased snorting sounds when your dog breathes. It is common for animals with a nasal discharge to snort or sneeze or they may paw at their face as if they are irritated or in discomfort. Other signs such as anorexia and weight loss can also occur depending on the underlying cause of the problem.

One of the most common causes of nasal discharge is allergic rhinitis. This is a bit like hay fever and your pet may have a continuous clear fluid trickling from their nose. Other signs are not very common with allergic rhinitis although your pet may occasionally sneeze. Over time a clear discharge may become more ‘snotty’ if a bacterial infection develops. This can be caused by respiratory irritants, such as smoke or dust or allergens such as pollens in the environment. If your pet suddenly starts to sneeze violently and then develops a nasal discharge it is more likely that they have a foreign body stuck in their nose, such as a grass seeds or a small object they have sniffed up. If your pet has nose bleeds or you notice flecks of blood in the discharge this may be a sign of a more severe disease such as cancer in the nose. Sometimes there may be swelling of the face over the nose and this is also likely to be a sign of more severe disease.

In very young animals a nasal discharge may develop if there is a congenital abnormality, such as a cleft palate, which allows a connection between the mouth and the nose inside the head. Food can then escape from the mouth into the nose and set up an infection. A very bloody discharge from the nose may actually be the result of a blood clotting disorder rather than any problem with the nose itself.

Infectious causes of nasal discharge are not common in dogs. However, dogs with long noses are prone to getting fungal infections in their nose. It is thought that the dog sniffs up the fungal spores when out walking which, in some dogs, lodge in the nose and start to grow. In this case the discharge may be thick and yellowish, but it is common for there to be signs of bleeding from the nose as well.

Your veterinarian may suggest some other tests to identify the cause of the discharge and help determine the severity of the condition. Imaging, such as x-rays, endoscopy or computed tomography (CT) are most useful to assess the structure of the nasal passages. CT scanning can be expensive but should be covered by pet health insurance if you have it. Your veterinarian will want to take a small sample of tissue from the lining of the nose (a biopsy) and this is usually done under general anesthesia at the same time as imaging. Analysis of this biopsy can help diagnose allergies, infections or tumors.

Blood tests can show your pet’s overall health and rule out any blood clotting disorders if the discharge is very bloody.

General treatments include cleaning the nostrils, nutritional support, oxygen therapy (if your pet is having difficulty breathing), nebulization (this can be used to moisten secretions and also to deliver some medications), and anti-inflammatories/pain relief.

More specific treatments may be appropriate for certain diseases, eg antibiotics for bacterial infections, antifungal drugs for fungal infections. The treatment of choice for nasal tumor is radiotherapy so referral to a specialist cancer center would be needed in this case.

As with most diseases, the prognosis depends on the cause and extent of the disease.

Some nasal diseases are readily treatable, while others carry a very poor prognosis. For example, if a nasal foreign body is removed and the associated infection treated early, the prognosis for a full recovery is good. If the disease has been present for a long time, there may be permanent damage to the inside of the nose and a complete cure may not be possible and signs may recur. Unfortunately, it is rare for nasal tumors to be cured by treatment, but remission times can be long during which your pet may return completely to normal.

There are a range of diseases that can affect the nose of domestic pets and many of these result in some form of nasal discharge. Early diagnosis and treatment are important to ensure that your pet has the best chance of recovery.