CHRONIC NASAL DISCHARGE IN CATS
Chronic upper respiratory tract (URT) disease is relatively frequent in cats. Most commonly, it follows on from viral infection ("cat flu") - the viruses cause the initial mucosal damage, but long term signs relate to secondary bacterial infection of damaged nasal passages. More unusual causes include fungal infections such as Cryptococcus, inflammatory polyps, neoplasia (cancer) and damage from foreign bodies, trauma or dental disease.
CLINICAL SIGNS
The clinical signs of chronic URT disease are mainly nasal discharge and noisy or difficult breathing or sneezing. A thorough physical examination by the veterinarian is needed to diagnose the extent and cause of the disease. Many factors give the veterinarian clues to the cause - if discharge is present, its nature (clear, blood-stained or purulent), and whether it is unilateral or bilateral, the presence of facial swelling or pain, the presence of ocular disease, evidence of painful or infected ears or dental disease, history of weight loss and enlargement of lymph nodes. Sometimes there is a history of previous "cat flu".
DIAGNOSIS
If, after examining the cat, the veterinarian feels that chronic post-viral rhinitis is the cause of the clinical signs, and the cat is not too distressed, no further investigation may be recommended. Further examinations are recommended for cats with severe or progressive clinical signs, or those with evidence of more widespread disease.
Further investigation begins with non-invasive tests such as haematology, biochemistry and tests for FIV (Feline Immunodeficiency Virus) and FeLV (Feline Leukaemia Virus). The next step is examination under general anaesthesia, which allows the veterinarian to look up the nose, examine the back of the throat and behind the soft palate, and also a more thorough examination of the teeth and ears. The skull and nasal cavities can be x-rayed and biopsies and swabs taken for examination and culture.
These procedures make it possible to differentiate between possible underlying causes, so the probable outcome is known and correct treatment given.
TREATMENT
When a specific cause has been found, sometimes a cure is possible, for example, polyps can be surgically removed, some cancers can be controlled with chemotherapy and fungal disease can be cured with anti-fungal drugs. However, since most cases of URT disease will result from chronic post-viral damage, the likelihood for full recovery, even with treatment, is guarded. In most cases, the clinical signs can merely be controlled, since the chronically damaged nasal passages cannot be repaired.
Antibiotics can be given to reduce secondary bacterial infection. It is usually necessary to give them for long periods of time or as repeated courses in order to control the clinical signs. Other treatments include mucolytics and steam inhalation, which reduces the thickness of nasal secretions and helps the cat breathe more easily.
The most important part of treatment is good nursing care, keeping the cat's face clean and clear of discharge and encouraging it to eat by feeding strong-smelling food that is slightly warmed.