What is it?
A cough is a really common symptom; however, it's a symptom not a disease! Coughing is a protective reflex - if anything irritates the airway, the dog will cough to try and clear mucus or debris from their lungs and windpipe. However, many different disease conditions can trigger a cough, so it's always worth getting it checked out.
What causes it?
Any source of irritation to the airway or throat can potentially cause coughing. The most common causes in dogs include: (1) Kennel Cough - a very common infection of the trachea (windpipe) and larynx (voice box); any dog can be infected (although vaccinated dogs are less likely to be ill) and the condition is very contagious. (2) Chest infections and pneumonia are uncommon but do occur in dogs; typically, the dog will be ill in themselves. (3) Heart failure is the commonest cause of coughing in older dogs - caused by an enlarged heart pressing on the trachea, and also an accumulation of fluid in the lungs (pulmonary oedema). (4) Lung tumours can also cause a cough; in dogs (who rarely smoke tobacco!), lung cancer is usually secondary to another tumour elsewhere. (5) Tracheal Collapse Disorder (commonest in toy breed dogs) also causes a characteristic cough, as the windpipe collapses and the dog coughs to try and inflate it. (6) Lungworm (both Dog and Fox Lungworm) can cause coughing, and are being increasingly diagnosed in the UK - although the distribution is rather patchy. (7) Inhalation of food - most common in dogs with laryngeal paralysis, but it can happen in dogs who are just excessively greedy and gobble their food!
What dogs are at risk?
Any dog can get a cough! However, heart disease and lung tumours are more common in older dogs, whereas kennel cough seems to be a bit more common in young adults. In addition, a dog who is vaccinated against kennel cough is less likely to develop the disease than one who isn't.
What are the symptoms?
The type of cough can sometimes help to diagnose the cause (although beware of relying on this on its own!). Tracheal collapse usually causes a "honking" type cough, as does Kennel Cough (which may also be described as a barking cough). The cough in Kennel Cough can often be induced by gently feeling the larynx and windpipe in the neck. On the other hand, a cough caused by heart failure tends to be soft and almost apologetic. Other symptoms may also be relevant - for example, a dog with pneumonia will be systemically ill in themselves with a fever, lethargy and depression; whereas dogs with heart failure are more likely to have exercise intolerance.
How is it diagnosed?
Physical examination and listening to the chest with a stethoscope will give us a lot of information; however, additional tests are often needed - typically X-rays of the chest and ultrasound scans of the heart. Blood tests for infection, lungworm and heart function are also available.
How can it be treated or managed?
It depends on the exact cause - for example, a chest infection would need antibiotics, whereas heart failure requires heart medications. We rarely look to suppress the cough itself (because in many cases it is doing its job in removing mucus and infectious material from the chest), but if needed, there are drugs we can use. NEVER use human cough syrups in your dog unless your vet has recommended it!
Can it be prevented?
The risk of Kennel Cough can be minimised with vaccination and isolation of infected dogs; and lungworm can be prevented with certain spot-on medications, but otherwise no.