Nasal and Nasopharyngeal Polyps in cats
Nasal polyps refer to protruding pink polypoid growths that are benign (not cancerous), and that are found to arise from the mucous membranes - the moist tissues lining the nose. Nasopharyngeal polyps refer to similar benign growths, but in this case may be found extending into the ear canal, pharynx (throat), and nasal cavity. Kittens and young adult cats between the ages of four months to approximately seven years are especially susceptible to the development of nasopharyngeal polyps.
The symptoms caused by nasal polyps can mimic illness, but do not respond to antibiotic therapy.
Symptoms and Types
- Nasal congestion
- Nasal discharge that is unresponsive to antibiotics
- Decreased nasal airflow
- Noisy breathing, especially when inhaling
- Many of the same symptoms as nasal polyps
- Trouble with swallowing (dysphagia)
- Trouble breathing in (dyspnea)
- Frequently tilting head to the side
- Ear infection, inflammation of the ear canal (otitis)
- Symptoms of Horner's Syndrome: drooping of eyelid, sunken eye, protruding third eyelid, abnormally small pupil
The causes of nasal polyps are unknown. It is suspected that congenital processes may be to blame (in which the tendency to develop this type of condition is passed on to offspring while in utero), or alternately, that these may develop secondary to chronic inflammatory processes.
If nasal or nasopharyngeal polyps are suspected, in many cases the cat will need to be anesthetized so that a veterinarian can examine the palate (the roof of the mouth cavity) in search of evidence of polyps. Another diagnostic procedure is a caudal rhinoscopy, in which a spay hook and dental mirror, or flexible endoscope (a thin rod with a small camera attached), is inserted into the nose for examination. A rostral rhinoscopy also allows for visualization, while also making it possible for your doctor to take tissue samples so that a biopsy analysis may be taken of any apparent masses. This is in order to differentiate the mass as benign or malignant (cancerous).
Additional diagnostic tests may include X-rays, computed tomography (CT) or magnetic resonance (MRI) scans in order to detect lesions of the nasal cavity, or nasopharnyx. These imaging techniques are especially useful in pinpointing other causes for the cat's symptoms.
If nasal polyps or nasopharyngeal polyps are not found to be responsible for the cat's symptoms, alternate diagnoses may include an obstruction in the upper airway, a neurologic disease, or a foreign body in the airway.
The primary method of treatment for nasal or nasopharnygeal polyps is surgery. It is important that both the root and base, or stalk, of the polyp are completely removed in order to prevent recurrence. After surgery, medications will be prescribed to prevent secondary bacterial or yeast infection of the affected areas. Your veterinarian can recommend the appropriate drugs based on a culture from the removed mass and sensitivity testing.
Living and Management
After the initial treatment, your cat's symptoms should be closely monitored for recurrence of the polyps. It is not uncommon for recurrence due to incomplete removal of a polyp or the stalk it grew from. However, if removal was complete, the prognosis for all patients is generally excellent.
Because the cause of nasal polyps and nasopharyngeal polyps are not known, there is no specific prevention technique that can be recommended.