It is not uncommon for dogs to cough occasionally. However, if your pet is coughing frequently or has persistent episodes of coughing then you should seek veterinary advice. There are many causes of coughing and many of these can be treated successfully. Some dogs occasionally cough when they get excited or pull on their lead. Many causes of coughing if left untreated, can progress over time causing severe consequences for your pet. If your dog develops a constant cough, an intermittent cough that does not get better after 2 weeks or becomes at all unwell then you should make an appointment to see your vet.
The trachea (also known as the wind pipe) is a tube that runs from the throat down into the chest where it branches to form the major airways in the lungs. The normal trachea is a soft tube that is held open by numerous rigid rings of cartilage. Coughing is the result of irritation or inflammation of the sensitive lining of any part or the airways or the lungs, and is an important protective mechanism allowing the removal of foreign material and mucus from the airway.
In young animals coughing is more likely to be caused by an infection, as a result of the dog inhaling a foreign body (such as a grass awn) or irritation due to smoke or other irritants. Some dogs have a congenital problem with their trachea which can allow the trachea to collapse and obstruct their airway so that they cough every time they get excited or pull on their lead. Brachycephalic dogs (those with short noses like pugs) may have long term respiratory problems that cause persistent or intermittent coughing.
In older animals other causes of coughing, such as heart disease and tumours, become more common. However, chronic bronchitis and other long term diseases reflecting damage to the respiratory tract over a lifetime can also develop in later life. A cough associated with chronic airway disease may be persistent but not get worse and your pet may remain bright and well otherwise.
Older dogs may also develop damage to the nerve controlling the vocal cords and these can obstruct their airway causing coughing particularly after eating, drinking or swimming if food and liquids pass into the airways instead of the oesophagus (the food pipe or gullet).
If your dog is coughing it is really important to get your vet to check them over to identify any possible causes that require treatment or to reassure you that nothing more serious is going on.
Some dogs with a cough may be completely normal in other respects, but this depends entirely on the underlying cause of the cough. In a young, otherwise healthy dog, kennel cough (infectious tracheobronchitis) is the most likely cause of cough. This usually gets better without treatment in 1 to 2 weeks but if coughing is persisting beyond this time or your pet is unwell you should seek veterinary advice. If you are taking your dog to the vet and think there is any possibility your dog may have kennel cough then it is advisable to leave you dog in the car until the vet has examined your dog, rather than risking potentially passing it to other dogs in the waiting room.
Dogs with pneumonia may have a fever, be off their food and feel pretty miserable. Nasal discharge may be present and this can be clear or snotty. Dogs with heart disease or lung problems may also have breathing problems and be unable to exercise normally. If laryngeal paralysis is present the changes to the vocal cords can cause changes in the tone of a dog’s bark (generally sounding hoarse), and exercise intolerance with some dogs developing blueness of the membranes (cyanosis) in their mouth or even collapse after exercise.
When presented with a coughing dog your vet will first want to establish some information which may help then localise which part of the respiratory tract is affected. Questioning you about the nature of the cough (whether it is dry or moist, intermittent or always present) will provide valuable information so it is important you think about the circumstances in which your dog coughs before you attend the veterinary visit. If you are able to take a video clip of your dog coughing on your mobile phone this may help your vet further. Your vet will want to examine your pet and look for any other signs of illness such as fever which may give a clue as to the cause of the cough. By listening to your dog’s chest with a stethoscope your vet will be able to assess heart and lung health. There are many diseases that can cause chronic coughing and your vet will want to rule out the more serious causes of coughing before a final diagnosis is made.
Investigation of coughing involves X-rays of the trachea and the chest and your vet may want to pass an endoscope (a small tube with a camera on the end) through the trachea and down into the lungs to take some samples; these are usually washes to look for inflammatory or cancerous cells, and to provide material for culture.