What is a cough?
A cough is an expiratory effort producing a sudden, noisy expulsion of air from the lungs, usually in an effort to free the lungs of some foreign material (real or imagined). This can sometimes be confused with retching or gagging, although occasionally an animal may retch or actually vomit following a forceful bout of coughing. The presence of a terminal retch may be misinterpreted as evidence of a problem with the digestive system.
Why do cats cough?
In cats, coughing is generally regarded as a sign of a problem affecting the lower respiratory tract, especially some form of bronchitis. Cats can cough for a variety of reasons, including the presence of foreign material within the airway (e.g. pieces of inhaled grass), or irritation from inhaled liquids or gases. Coughing can also result from inflammation of the airway, which may be acute (e.g. cat ‘flu) or more chronic (e.g. chronic bronchitis). The inflammation may be caused by a number of factors, including viral, bacterial, or parasitic worm infections, or may be associated with an allergic reaction. Tumours (cancer) located within the chest can occasionally cause coughing. In cats coughing is rarely associated with heart disease, although some cats with hypertrophic cardiomyopathy are presented for coughing as the main sign of disease.
Coughing can also be seen with upper respiratory tract disease, e.g. where irritation, inflammation or other disease affects the larynx or trachea, or where disease in the nose results in excessive secretions draining into the larynx and trachea, hence causing irritation and coughing.
When does a coughing cat need veterinary attention?
It is important to remember that it is normal for all cats to cough occasionally, e.g. when they inhale or aspirate foreign objects, or if their airway becomes irritated by changes in the environment. If the cat only coughs occasionally, is well in itself, and the cough is not productive, it does not require treatment. However, if the cough persists for more than a few days, is severe, productive (i.e. the cat spits something out, or swallows at the end of a coughing fit), the cat appears unwell in itself, or is loosing weight, then Veterinary attention should be sought.
How can the Vet find the cause of a cat’s cough?
Most acute cases of coughing will cure with minimum need for interference, except for perhaps a 7-14 day course of antibiotics. However, if the cough is very severe, or if it has been present for some time, then further investigation may be needed. This usually entails taking a full and detailed history which may help to high-light the underlying cause (e.g. a cat allergic to human skin dust may cough mainly when lying on it’s owner’s bed). The Vet will need to know whether the cough has changed over time, and whether the cat has any other medical problems that may be significant. The cat may then be given a general anaesthetic, so that it’s chest can be radiographed. While the cat is anaesthetised the Vet may look down it’s airway with an endoscope. Samples of fluid and cells can be collected from the airway, either via the endoscope, or by flushing a small amount of sterile salt solution into the lungs and then sucking it back out again. These samples can be used to look for the presence of infection, inflammation or tumours.
How can the cough be treated?
How a particular cat is treated depends on the cause of its cough. In the case of a mild bacterial infection, a course of antibiotics is likely to be sufficient. The removal of a piece of foreign material, or the correct drug treatment for lung worm infection, will also result in a cure.
Once coughing becomes a chronic problem (i.e. has been present for over 2 months), the likelihood of bringing about a total cure is not so good. This is because chronic coughing is associated with chronic inflammation of the airway, often due to chronic exposure to allergens (particles to which the cat is allergic), irritants (e.g. cigarette smoke), or bacterial infection. This chronic exposure results in a number of changes in the structure of the cat’s airway, such that even if the initial trigger can be identified and removed, the damage has already been done and the lungs can never fully recover. In these cases treatment aims to control the coughing, and prevent further damage. It may include removing any known irritants or allergens, giving drugs (bronchodilators) to help keep the airways open, treating bacterial infections with antibiotics, reducing inflammation with corticosteroids, and sometimes giving decongestants. In the case of certain types of cancer, chemotherapy or surgery may be an option.