Nose and Sinus Inflammation in Cats

Inflammation of the nose and sinus is a common and sometimes serious problem in cats. It can be a primary condition acute in nature, but more often it is a result of a systemic disorder such as infection. Occasionally, it can be idiopathic, meaning its source is unknown, which makes treatment more difficult. Chronic rhinosinusitis may persist over the life of your cat. It can be a challenge to manage and there is no cure. However, nose and sinus inflammation is rarely life-threatening to cats and is often easily treated with medication unless there is a serious and chronic underlying condition associated with it. In such cases, treatment will include addressing the symptoms and causes of the identified disorder.

When the lining of the mucous membranes of the nose is inflamed, the condition is called rhinitis. Inflammation of the lining of the sinuses is termed sinusitis. The two conditions often occur together, creating rhinosinusitis, but not always. Left untreated, the condition can inhibit the function of the mucous membranes of the nasal passages, leaving the lungs to handle the filtering of dust and microorganisms, which often leads to repeated respiratory tract infections.

A runny nose and sneezing may be your first signs of rhinosinusitis in your cat. You should not dismiss the condition as a mere common cold if you also see these other symptoms: 

• Nasal discharge
• Sneezing, frequently episodic
• Stuffy nose
• Bleeding from the nose
• Dehydration
• Respiratory noise while inhaling
• Discharge and tears from the eyes 
• Conjunctivitis
• Labored breathing, possibly with open mouth breathing
• Coughing
• Vomiting
• Loss of appetite

Signs are often recurrent and chronic.

Feline herpes viral rhinotracheitis and feline calicivirus infection are the most common causes of acute rhinitis and sinusitis in cats, although other viruses could also be at fault. Bacterial infections often occur after the initial onset of a viral infection. Other possible causes are:

• Fungal infection, especially Cryptococcosis 
• Parasites
• Presence of a foreign object
• Blocked nasolacrimal duct in the nose
• Indoor and outdoor allergies 
• Dental disease
• Trauma
• Systemic hypertension
• Vasculitis
• Nasopharyngeal or sinus masses including polyps
• Genetic defects such as palate abnormalities
• Impaired immune system
• Cancer

A basic physical examination will first be conducted, which will include examination of your cat’s nose and nasal cavity, eyes, mouth, and ears. Your veterinarian will be looking for evidence not only of swelling, but also of polyps, dental disease, and infection. If clinical signs indicate any of these, additional testing will be needed to identify the underlying cause. 

A complete blood count, urinalysis, and serum biochemistry will be performed to test for viral, fungal, and bacterial infections. Feline leukemia virus and feline immunodeficiency virus are common causes of chronic rhinitis and sinusitis and can be detected through blood tests. Your cat’s blood pressure will be monitored to assess for hypertension, and a polymerase chain reaction (PCR) test may be performed to check for herpesvirus 1 and calicivirus, both common causes of upper and lower respiratory diseases in cats.

If there are signs of concern, your veterinarian may decide to perform x-rays, a CT scan, or an MRI scan of the skull to further check your cat’s nasal passages, sinuses, dental health, and overall bone health. These tests will be conducted under anesthesia. A rhinoscopy or a nasal biopsy may also be done at this time to further exam your cat. A rhinoscopy will help to identify any congenital disorders, and a biopsy taken from the back of the nasal cavity will aid in determining the presence of a bacterial or fungal infection. 

Slide samples of mucus from the nose may be taken for testing, but the results are not always conclusive since it is often difficult to distinguish between the negatively affecting agents and the good flora in the nasal passages. However, a culture and sensitivity of the discharge is definitely worthwhile.

Although there is no cure for rhinitis and sinusitis, topical and systemic antibiotics along with antihistamine and anti-inflammatory medications such as glucocorticoids and NSAIDS will help to reduce the symptoms in mild, acute cases. The length of treatment is dependent on your cat’s response. Chronic conditions may be treated symptomatically and with environmental management.

If the condition has severely progressed, intravenous fluids may be necessary to prevent dehydration and nutritional support given through a feeding tube to stop or prevent weight loss. Treatment will then be more directly addressed toward the underlying cause. 

Usually, rhinitis and sinusitis are treated with medication and environmental modification, as well as supportive care. Your veterinarian may discuss surgical options with you if your cat is not responding to antibiotic therapy, however. Radiation therapy may also be an option, depending on the underlying cause of the inflammation.

Since antibiotics have no effect on viruses, they won't always be issued. However, they will be needed if there is a secondary bacterial infection, which would not be uncommon.

Your veterinarian may choose to administer a feline herpesvirus vaccine that may help shorten and minimize recurrence of symptoms of infection in the future. It is not a preventative treatment and is only meant to lessen your cat’s symptoms. 

Rhinosinusitis caused by a fungus can be treated with antifungal therapy once the particular source has been identified. Note that chronic rhinosinusitis along with fungal infection may require a longer course of treatment, possibly 4-6 weeks or more.

Acupuncture therapy could potentially relieve rhinitis and sinusitis for some cats.

The prognosis for primary bacterial sinusitis and rhinitis is excellent, with symptoms resolving within two weeks of treatment. The prognosis for secondary conditions is dependent on how successful the treatment is for the underlying cause. If the cause is unknown, symptoms may reoccur with varying response to treatment. 

Discuss with your veterinarian all available options as well as predictions for outcome and how you may best provide care to your cat if your cat is experiencing chronic rhinitis or sinusitis along with a systemic disease.

You can help to support your cat’s immune system through good nutrition, routine vaccinations, practicing good hygiene, keeping a clean home and maintaining clean air that is free of dust, smoke and fumes.