Rhinitis is a generic term for inflammation of the nasal mucosa and passages. There are many causes of rhinitis, fungal, bacterial, allergies, bacteria, viral just to mention a few. Viral infections are the most common cause of rhinitis in companion animals. The most common viral culprits are Feline viral rhinotracheitis (FVR), feline calicivirus (FCV), canine distemper, canine adenovirus types 1 and 2, and canine parainfluenza. Chronic rhinitis can be seen in cats with  FVR and FCV, flare ups are often associated with times of stress. Bacterial rhinitis or sinusitis is frequently seen as a secondary complication of chronic rhinitis in cats. Primary bacterial rhinitis is very rare in dogs. Smoke aspiration, seasonal or environmental allergies, inhalation of irritant gases and dusts, or foreign objects lodged in the nasal passages also may cause acute rhinitis.

Cases of chronic rhinitis usually have intermittent but recurrent episodes of nasal discharge accompanied by sneezing. There may be a partial response to antibiotics if there is a secondary bacterial infection present, however the signs will not resolve entirely. 

Signs of rhinitis may include sneezing, pawing at the face snoring, an audible nasal congestion, and/or a nasal discharge. Some pets may breathe with an open mouth due to obstructed nasal passages and may experience shortness of breath. Sneezing with or without nasal discharge is the most common sign of rhinitis. Some animals will also exhibit runny or watery eyes due to inflammation of the facial sinuses. 

Diagnosis of rhinitis is based on a history of the aforementioned symptoms and physical findings. In some cases of severe rhinitis a procedure called a rhinoscopy may be recommended. A rhinoscopy is a procedure where a small camera is passed into the nasal cavity to visualize the nasal passages and sinuses. During this procedure swabs for culture or small biopsy samples may be taken. Computerized tomography (CT) may also be useful to image the frontal sinuses to look for tumors or other physical abnormalities. 

Treatment of rhinitis is dependent upon the causative organism. Medications such as antihistamines, antibiotics, antifungal agents or steroids may be used. In cases of a nasal foreign body  or a nasal tumor sedation for removal or a surgical intervention may be required. 

Chronic viral rhinitis as seen in cats is managed symptomatically, by supporting the overall health of the cat with proper nutrition and a cleanly litterbox environment. In severe cases hospitalization for fluid and nutrition support (cats with severe rhinitis often stop eating due to lack of ability to smell their food).