Causes of Yellow/Green Discharge from Your Cat’s Nose

Why do cats develop nasal discharge?

The nasal passages are subjected to environmental irritants and allergens every day and have innate defense mechanisms to help them fight these off and prevent them from affecting the lower airways. These defense mechanisms work in different ways to prevent any pathogens, irritants, and allergens from traveling further down the respiratory tract and causing more serious respiratory problems.

The inside of a cat’s nasal passages is lined with numerous thin hair strands, called cilia, that help trap pathogens or environmental hazards when accidentally inhaled by the animal. These cilia constantly move in an outward direction to help push out foreign materials that have entered the cat’s nasal passages.

Along with the cilia in the nasal lining, there are also mucosal cells along the epithelium of the nasal passages. These mucosal cells produce mucoid discharges that help further trap foreign material and pathogens. This also allows the nasal ciliary lining to remove these inhaled materials more easily.

Lastly, any irritation along the lining of the nasal passages causes a mild inflammatory response which usually triggers sneezing in affected cats. Sneezing propels any trapped foreign bodies, pathogens, and environmental irritants away from the upper airways and clears the animal’s nasal passages. Cats that have chronic nasal irritation or inflammation, medically known as rhinitis, often present with frequent sneezing and profuse nasal discharges.

Common Causes of Nasal Discharge in Cats

The type and physical properties of nasal discharges a cat produces can vary greatly depending on the type of pathogen or irritant that could have triggered the immune response. The most commonly seen nasal discharge in cats is clear, colorless, and often runny. Cats that produce this kind of nasal discharge are often seen excessively sneezing but do not show any other signs of illness.

Clear, colorless, runny nasal discharge in cats is usually an indication of a mild inflammatory or allergic reaction along the epithelial lining of the nasal passages. The serous nasal discharge produced due to inflammation helps the cilia of the nasal lining to remove the irritant that triggered the inflammation or allergic reaction.

Nasal discharge in cats can also appear mucoid, thick, and yellow or green in color. This is commonly seen in young kittens and adult cats with some sort of viral or bacterial infection. Many pathogens can cause a mucoid and green discharge in cats.

Primary bacterial respiratory infections, also known as Feline Upper Respiratory Infections (URI) are often localized infections causing respiratory signs such as sneezing, nasal discharge, and coughing. In some cases, mild signs of systemic illness such as weakness and a decrease in appetite are observed in infected cats.

Primary bacterial infections of the upper respiratory tract and nasal passages are the most common cause of green, mucoid, nasal discharge in cats. Several bacterial species like Chlamydia sp., Bordetella sp., and Mycoplasma sp. are commonly isolated in upper respiratory tract infection cases in feline patients. These bacteria are the primary reason for the green color of the nasal discharge infected cats produce.

Certain viral diseases like Feline Herpesvirus or Feline Calicivirus infect the upper respiratory tract of unprotected cats, resulting in severe mucoid nasal discharges. Secondary bacterial infection is common in viral diseases, resulting in the production of green mucoid nasal discharge. Cats and kittens with confirmed viral infections often have moderate to severe signs of systemic illness like lethargy, inappetence, and breathing difficulties.

Diagnosis and Treatment Options for Cats with Nasal Discharge

Cats with nasal discharge need to be seen by a vet, regardless of the color and physical properties of the discharge they produce. Your vet will determine the underlying cause and will propose a treatment plan depending on the diagnosis.

A thorough physical exam by your vet will help isolate the parts of the respiratory tract that are affected and determine if the cause is localized or systemic in nature. A blood test may be requested by your vet to assess how severe the infection is. Radiographs (x-rays) can help determine if the lower respiratory tract is affected.

Specific tests for viral diseases using the nasal discharge as samples can help confirm the diagnosis of viral infections. Bacterial culture and isolation can also determine the specific bacterial species in cases of upper respiratory tract infections. In cases of infectious underlying causes, specific antibacterial and antiviral treatments are available. Your vet may also prescribe or recommend symptomatic and supportive treatments to help alleviate the symptoms associated with the condition.

Nasal sprays and nebulization can help control excessive nasal discharge and help clear up the nasal passages. Anti-inflammatory medications such as corticosteroids help control signs of rhinitis which helps reduce the production of nasal discharge.

In any case, nasal discharge in cats warrants a visit with your vet, as some underlying conditions can be fatal if left undiagnosed and untreated for a prolonged period. A proper exam is necessary to determine the cause and provide appropriate treatment for affected feline patients.

Read more:

Bloody Noses in Dogs and Cats

Top 3 Causes of Conjunctivitis in Cats

Common Diseases in Cats

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