Chronic rhinosinusitis is characterized by chronic, intermittent and/or recurrent episodes of sneezing/sniffling and nasal discharge, often occurring for months to years with only a partial response to various antibiotic treatments.  Nasal secretions containing pus or blood are common and can involve one or both nostrils.

These symptoms happen as a result of destruction of the nasal bones and the proliferation of nasal mucous glands resulting in continuous mucous production. Viral infections often initiate the condition. Then, bacteria follow and infect the damaged mucous membranes. Recurrent infections are common due to the failure of antimicrobials to penetrate infected cavities that contain resistant organisms, or because of tenacious, thick discharge that drains poorly. In chronic cases, it is rare to determine a single cause that can be specifically treated and cleared from the body. 

A diagnosis of chronic rhinosinusitis requires ruling out other diseases that produce nasal discharge such as foreign bodies, dental abscesses, nasopharyngeal polyps, neoplasia (cancer), and fungal infections, all of which can have similar clinical signs.

The diagnostic evaluation begins with a complete physical examination. It may be followed by an examination under anesthesia of the mouth, nose and ear canal. These examinations are followed by appropriate tests that may include:

1. Feline Leukemia and Feline Immunodeficiency Virus tests

2. Complete Blood Count

3. Comprehensive metabolic profile 

4. Radiographs under anesthesia (dental, skull and sinus cavities, and/or chest)

5. Cytology & culture of secretions

6. Endoscopy & biopsy

7. Advanced imaging (CT scan)

Therapeutic goals are: improve nasal/sinus drainage, reduce mucus formation, and control infection and inflammation. In most cases, clinical signs can be improved but not resolved. Symptomatic treatment strategies may include:

1. Strategic systemic antibiotics for six to eight weeks (pulse therapy may be used)

2. L-lysine powder mixed with food to slow herpes virus replication

3. Saline nasal drops (Little Noses®), one or two drops as required

4. Steam nebulization (placing cat in a steamy bathroom) can reduce the viscosity of the secretions and encourage productive sneezing

5. Saline nebulization (nasal steroid preparations may be added to saline)

6. Nasal flush under anesthesia to remove thick mucoid material

Due to the frequent occurrence of multiple and changing etiologies involved in this chronic, challenging disease, remission rather than a cure is the goal of therapy.