Persistent Cough

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Cough is a protective reflex of the lungs. The normal flow of air into the lungs is as follows; air enters the mouth or nose and then into the back of the throat, air then passes through the larynx and into the main windpipe known as the trachea, then into the first branches of the airways known as bronchi, then into small airways called bronchioles before moving into the alveoli where gas exchange occurs.

When a potential cough trigger enters the airways the cough reflex will expel that trigger. To improve the protective mechanism, cough works alongside the formation of mucous in the airway. This mucous will trap small particles such as bacteria or viruses and with help of the cilia in the airways, this mucous will be moved out of the airways.

When should I consider cough to be a problem?

Occasional cough, such as a couple of episodes during a day without cough the subsequent days or cough when pulling a lead when using a collar can also be normal. If the cough becomes more frequent and affects your pet’s daily routine, then this is considered a problem. Several clinical reasons can be behind the manifestation of cough and often several investigations are needed to find the problem.

What are the causes of cough?

The most common causes of cough are infectious diseases of the airways, in dogs, “kennel cough” and in cats “cat flu” are the most common infectious diseases of the airways. In the area where our hospital is located, lungworm, Angiostrongylus vasorum, infection is also a common infectious cause of cough.

Chronic inflammatory conditions such as chronic bronchitis in the dog and chronic bronchitis / asthma in cats are encountered occasionally and may require lifelong medication. In middle age to older patients, degenerative diseases such as static or dynamic tracheal and/or bronchial collapse are more frequent, especially in small breed dogs. Other possible causes of cough include heart conditions or lung diseases including some cancerous conditions.

What investigations are performed to determine the cause of cough?

There are a number of different types of tests which can be used to determine the cause of cough. Hearing you dog breath, watching videos of your dog’s cough and listening to your dog’s lungs using a stethoscope can often help determine which type of investigations may be needed. Imaging of the chest if often required, and sometimes several different types of imaging study are needed. X-rays and chest CT imaging give information regarding the structure of the lungs, and watch a cough using fluoroscopy which is a modality which films breathing using X-rays can be very useful. Often some samples from the lung may be needed, and this may require a fine needle sample of any lung lesions or performing a lung wash. There are occasions when a lung biopsy or removal of a lung lobe are needed.

How can cough be treated?

Depending on the underlying condition, treatment may require daily medications, that may be life-long, or interventional procedures. Cough suppressant medication can sometimes be used if there is no infection.

What can I do to help my pet with cough?

Special attention should be paid to your pet weight. If your pet is overweight then a weight reduction program is key in cough control. Gentle walks are also important to help weight reduction and to promote mucous clearance. When on a walk, a harness should be used instead of a collar.

Avoid exposure to any known triggers of their cough, as well as smoke, air fresheners, scented candle, dust, or intense perfumes. Carpets should be vacuumed regularly.