Nasal allergies are characterized by periodic bouts of sneezing that last a short time and tend to recur day to day. Usually, there is a clear watery discharge from the nose. Most cases are caused by contact with environmental irritants and allergens. It makes sense to look for causes of this irritation. Cigarette smoke, dust, and pollen are common causes. A new carpet cleaner, deodorant powders or sprays, or even a new laundry soap could be the cause of nasal irritation. True nasal allergies are thought to be uncommon by most veterinary experts, and most cases that appear to be allergies are actually reactions to irritants.
Treatment: If possible, simply remove the source of the irritation. If that is not possible, this type of rhinitis responds well to medications that contain steroids and antihistamines. Never give your cat a medication containing a steroid without consulting your veterinarian. The antihistamines chlorpheniramine or cyproheptadine may be helpful, and your veterinarian may suggest anti-inflammatory eyedrops, which can be applied intranasally.
Chronic inflammation leads to lymphoplasmacytic rhinitis (an influx of lymphocytes into the nasal tissues), which is fairly common in cats. Systemic anti-inflammatory medications, such as meloxicam or corticosteroids, may be needed for control. These chronic inflammatory conditions may contribute to nasal lymphoma, which is the most common form of nasal cancer in cats.
The cat has two frontal and two sphenoid (wedge-shaped) sinuses. The small sphenoid sinuses don't often cause problems. But because respiratory infections are common in cats, secondary infections of the frontal sinuses occur with some frequency.
Signs of a chronic bacterial infection include a persistent, purulent nasal discharge, often just from one nostril, accompanied by frequent sneezing and sniffling. X-rays may show increased density of one sinus. The cat may appear to have a headache and sit with his eyes partially closed and his head hanging. Diminished appetite, another sign, can lead to rapid weight loss.
An abscessed tooth (usually the root of one of the top premolars) can lead to an abscessed frontal sinus. This produces a painful swelling below the eye. This problem is not common in cats.
Fungal infections (cryptococcosis and aspergillosis) are uncommon causes of sinus infection in the cat. With cryptococcus infection you may see facial deformities and skin ulcers on the nose. Cryptococcus is often associated with exposure to pigeons, even if it is simply the dust of pigeon excreta blowing in an open window.
Sinusitis can be suspected from the clinical signs and is usually confirmed by an X-ray.
Treatment: Treatment with an appropriate antibiotic, based on culture and sensitivity tests, is indicated. Sometimes this is not successful. A surgical procedure, which involves making an opening into the sinus through the skin to aid drainage, may be required. Flushing the sinus and leaving it open to heal is another treatment option.
This article is excerpted from “Cat Owner’s Home Veterinary Handbook” with permission from Wiley Publishing, Inc.