Veterinarian Provides Detailed Explanation of Potential Causes of Nasal Discharge in Cats

A cat's nose is usually a little damp, but it doesn't typically run. If your cat's nose is running, it may be a sign of an underlying health issue.

Below is a detailed explanation of potential diseases that may cause a cat's runny nose.

Why Do Cats Get Runny Noses?

A cat's nose contains many glands that secrete fluids, keeping it constantly moist. Each time the cat breathes, foreign substances from the outside world can enter the nose. Nasal hairs trap these foreign bodies, which are then entangled in secretions and expelled, preventing them from entering the body. Additionally, the nose humidifies inhaled air, preventing dry air from reaching the lungs.

A runny nose indicates an excessive secretion of nasal fluids. The nasal discharge can change from clear to yellow or yellow-green. When immune cells in the nose capture pathogens, the discharge turns yellow or yellow-green. Therefore, a runny nose can signal an abnormality in the cat's body.

Should You Take Your Cat to the Vet for a Runny Nose?

A runny nose in a cat is often a symptom of an illness. You should take your cat to the vet immediately.

Here are some of the main possible diseases:

Feline Viral Rhinotracheitis

This is commonly known as cat flu. Feline Viral Rhinotracheitis is caused by the Feline Herpesvirus. While conjunctivitis is the main symptom, inflammation of the nose and trachea also occurs, leading to nasal discharge. Additionally, excessive tearing can cause tears to flow through the nasolacrimal ducts into the nose, appearing as a runny nose. Initially, the nasal discharge is clear, but it can change color if a secondary bacterial infection occurs.

The Feline Herpesvirus can remain latent in the nervous system, meaning the cat continues to be infected even after symptoms subside. In kittens, a blocked nose due to discharge can lead to breathing difficulties or inability to eat, which can be fatal.

Treatment primarily involves symptomatic therapy to manage the symptoms, though anti-herpesviral drugs or interferon may sometimes be used.

Feline Calicivirus Infection

This is also commonly referred to as cat flu. Feline Calicivirus infection is caused by the Feline Calicivirus. In addition to general cold symptoms in cats, a characteristic feature of this infection is the development of oral ulcers. Initially, clear nasal discharge occurs, but it can change color if a secondary bacterial infection develops.

Feline Calicivirus can persist in the body for a long time, leading to continuous shedding of the virus. In kittens, a blocked nose due to discharge can cause breathing difficulties or inability to eat, which can be fatal.

Since there is no specific antiviral drug for calicivirus, treatment mainly focuses on symptomatic therapy and interferon therapy.

Feline Cryptococcosis

Cryptococcus is a type of fungus. If the immune system is healthy, cryptococcosis usually does not occur. However, if a cat has feline AIDS or feline leukemia, or if its immune system is weakened by immunosuppressants, it can become infected.

Cryptococcus infects the cat's nose and lungs, causing respiratory symptoms like sneezing and nasal discharge. Cryptococcus can form masses in the nose, which may lead to facial disfigurement.

Treatment involves the use of antifungal medications.

Allergic Rhinitis

Cats can also suffer from allergic rhinitis. Common triggers include environmental allergens such as pollen and house dust. It often has a seasonal pattern, occurring in spring or autumn. A characteristic symptom is clear, watery nasal discharge.

Treatment involves the use of steroids and antihistamines. Additionally, regular use of flea and tick preventatives and meticulous cleaning of the indoor environment are recommended.

Dental Disease

While teeth and nose may seem unrelated, they are deeply connected.

Only a portion of the tooth is visible; most of it is embedded in the jawbone. The embedded part is called the tooth root. Cats often develop periodontal disease, an inflammation of the gums, which can lead to pus accumulation at the tooth root if it worsens. The roots of the upper teeth extend close to the nasal cavity. If pus accumulates, the bone can dissolve, creating a passage into the nose. This can result in purulent nasal discharge.

For mild periodontal disease, anti-inflammatory drugs or interferon preparations may be used. In severe cases, dental scaling under anesthesia or surgical removal of severely inflamed gum tissue may be necessary. If pus is confirmed at the tooth root via dental X-ray, tooth extraction is performed.

Nasal Tumors

In middle-aged and older cats, the incidence of nasal cavity tumors increases. Types of nasal cavity tumors include adenocarcinoma, squamous cell carcinoma, and lymphoma. Lymphoma tends to occur more frequently in cats infected with feline leukemia. Nasal cavity tumors form masses inside the nose, which can significantly alter the shape of the face and obstruct the nostrils. As the tumor spreads, it can even reach the mouth. Bloody nasal discharge may occur, and in severe cases, it can turn into foul-smelling, purulent discharge.

Treatment options include surgery, chemotherapy, and radiation therapy, varying depending on the type of tumor. However, in most cases, tumors are discovered at an advanced stage, leading to a poor prognosis.

Summary

A cat's runny nose is almost always caused by an illness. Pathological nasal discharge does not stop within a day or two; it persists. Especially in middle-aged and older cats, a runny nose could indicate a tumor. Do not dismiss it as "just a runny nose"; always take your cat to the vet.

In cases of allergic rhinitis, improving the environment and regular flea and tick control can help. It is crucial to follow your veterinarian's instructions for treatment.

Diseases causing a runny nose can also lead to changes in facial shape. It is important to observe your cat daily and seek veterinary attention immediately if you notice anything unusual.